N R & T R No 1 • 2005
News from Denmark, Finland, Iceland, Norway and Sweden
Fatigue – a traffic safety threat
Editorial notes Nordic Road & Transport Research is a joint publication of six public road and transport research organisations in the Nordic countries, Denmark, Finland, Iceland, Norway, and Sweden. The main objective of the publication is to disseminate research results and news from the institutions, especially to researchers and decision makers. Each institution is responsible for the selection and presentation of the material from its own scope of activities. Nordic Road & Transport Research is published three times a year. It is regularly sent out, free of charge, to recipients selected by the six joint publishers. Free sample copies are also sent out on special request. Reproduction and quotation of the texts are allowed if reference is made to the author and source. However, legislation regulates and restricts the right to reproduce the illustrations. Please contact the respective publishing institution for information. Advertising is not accepted. Correspondence about the contents of the publication: Please write to the author or to the respective publishing organisation. Requests for back issues, and notification of address changes: Readers outside the Nordic countries: please write to the Editor-inchief at the VTI in Sweden. Readers in the Nordic countries: please contact the publishing institution of your country. Addresses: see back cover. The Editorial Board consists of the following representatives of the publishing institutions
Volume 17 • No. 1 • June 2005
Danish Road Directorate (DRD) Danish Road Institute (DRI)
The Road Directorate, which is a part of The Ministry of Transport and Energy, Denmark, is responsible for development and management of the national highways and for servicing and facilitating traffic on the network. As part of this responsibility, the Directorate conducts R&D, the aim of which is to contribute to efficient road management and to the safe use of the network. The materials research component is carried out by the Danish Road Institute.
Technical Research Centre of Finland (VTT), Building and Transport
VTT Building and Transport, employing a staff of 450, is one of the eight research units of the Technical Research Centre of Finland (VTT), with a total staff of 3,000. VTT Building and Transport covers all fields of transport and road engineering. The unit is active in international research and has a prominent role on the national level.
Public Roads Administration (PRA), Iceland
The duty of PRA is to provide society with a road system according to its needs and to offer service aiming at safe, unobstructed traffic. The number of employees is about 340. Applied research concerning road construction, maintenance and traffic and safety is to some extent performed or directed by the PRA. The authority with its Research and Development division is responsible for road research in Iceland.
Norwegian Public Roads Administration (NPRA)
Denmark Helen Hasz-Singh, Danish Road Institute
The Norwegian Public Roads Administration is one of the administrative agencies under the Ministry of Transport and Communications in Norway. The NPRA is responsible for the development and management of public roads and road traffic, as well as the Vehicle Department. This responsibility includes research and development of all areas related to road transport, and the application of R&D products.
Finland Kari Mäkelä, Technical Research Centre of Finland, Building and Transport
Institute of Transport Economics (TØI), Norway
Editor-in-Chief Michael Höglund, VTI
Iceland Hreinn Haraldsson, Public Roads Administration Norway Thorbjørn Chr. Risan, Norwegian Public Roads Administration Harald Aas, Institute of Transport Economics Production: Johnny Dahlgren Grafisk Produktion AB Place of publication: Linköping, Sweden Issue: 3,500 ISSN 1101-5179 Cover photo: Sleepiness and Reduced Alertness as Risk Factors in Driving Photo Johnny Dahlgren
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The Institute of Transport Economics is the national institution for transport research and development in Norway. The main objectives of the Institute are to carry out applied research and promote the application and use of results through consultative assistance to public authorities, the transport industry and others. The Institute is an independent research foundation employing about one hundred persons.
VTI
carries out research and development work of an internationally high standard for the transport sector. Our work embraces all modes of transport. Our key expertise is in the fields of safety, economy, environment, traffic and transport analysis, behaviour and the human-vehicle-transport system interaction, as well as in road design and infrastructure maintenance. VTI is a world leader in several areas. The Institute is state-owned and has a total of 180 employees.
NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
CONTENTS VTI
24/7 Society Villain in the Fatigue Drama . . . . . . . . . . . . . . .4 Help for Drowsy Motorists . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Institute of Transport Economics (TØI)
Fatigue, Sleepiness and Reduced Alertness as Risk Factors in Driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Speed and Road Accidents: an Evaluation of the Power Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Effects on Speed and Accidents . . . . . . . . . . . . . . . . . . . . . .12 Danish Road Directorate (DRD)
NordFoU – A New Nordic Road Research Initiative . . . . . .13 Traffic Management and Noise Reductions . . . . . . . . . . . . .15 New Ideas to Reduce Road Traffic Noise in Cities . . . . . . . .18 Norwegian Public Roads Administration (NPRA)
The Impacts of Road Salt and other Highway Pollution on the Water Quality and Circulation Conditions in Lake Padderudvann . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Foamed Glass – an Alternative Lightweight and Insulating Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Technical Research Centre of Finland (VTT)
Implementation of Life Cycle Studies for Road Maintenance Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Annotated reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
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24/7 Society Villain Article written by Michael Höglund. For more information contact Anna Anund, e-mail: anna.anund@vti.se.
The average Swede sleeps less and worse than ever. Twenty percent of Sweden’s population have constant sleeping problems these days. More and more people are having sleep problems the closer we get to the 24/7 society. In addition, the Swedes’ sleeping problems are having a greater impact on road safety. Twenty-four hour access to all services is the major feature of the 24/7 society. TV, internet, radio etc. are available all day and all night long. Food stores and other shops are open longer and longer. Many people these days have irregular working hours with later evenings and nights. Drowsy and tired drivers on the roads cause approximately every fifth road accident. Fatigue on the roads is as dangerous as alcohol is in traffic. Professional drivers, shift workers and young people in the danger zone
Anna Anund at VTI is doing research into fatigue in traffic and feels that the problem of tiredness should be highlighted much more in order to make it possible to realise the vision of zero deaths on the road. Tiredness causes just as many accidents as alcohol does. The problem is a serious one, with approximately 40–50 people dying each year in accidents caused by driver fatigue. A great many people underestimate the danger of driving when tired and overestimate their ability to handle the situation. It is not enough with music playing, a cup of coffee and the window open to stay alert. The body needs to rest and drivers have to plan their driving accordingly. The drivers running the highest risk of being involved in an accident are young drivers and those people who drive for a living. Young drivers do less to stay alert and what they do has less effect. Profes4
sional drivers find it hard to stop and have a nap, mainly due to the tight schedules set by transport firms and partly out of fear of their load being stolen. Shift workers are also a high-risk group. Can we abolish the 24/7 society?
No, but we have to realise there are less positive sides to our night and day society which play havoc with people’s health. The problem of tiredness is one of these downsides. Many things could be done to reduce the risks with tired motorists. One strategic measure for example could be more information and training or maybe vehicles and the road environment could be designed so as not to contribute to driver drowsiness. One tactical move could be the introduction of rumble strips, grooved ribs in the road verge, to warn drivers. On the operative side, there are driver support systems that turn off the ignition if the driver falls asleep at the wheel to give just one example. A number of projects have just started which will reduce the number of accidents caused by driver fatigue.
the information could be for instance, noise from rumble strips, grooves in the road verge, or noises from various types of support systems. However, the driver has to be motivated to make these effective moves. Various driver support systems
Driver supports are technical systems designed to detect driver tiredness and drivers who are falling asleep. The system would react for example by giving off signals or stopping the vehicle. The driver’s blinking duration can be measured by the driver support system to determine whether a driver is starting to get tired or is falling asleep. The car would then let the driver know using different kinds of signals. Another way would be to monitor the driving behaviour of the driver, i.e. how the vehicle is kept on the road by monitoring driver behaviour at the wheel. The system would warn the driver either with a signal feedback system or by intervention such as bringing the vehicle to a stop.
It is vital to inform drivers
The road environment and the world around it
It is of great importance to focus information and training efforts on young drivers and people driving for a living, and even those who have influence over the working conditions of professional drivers. The top priority is to make drivers realise the risks of driving while tired. – One potential move is to increase drivers’ awareness that when you are tired, you lose your power of judgement. This leads to underestimating the risks and overestimating your own ability. This should be a natural part of driving schools’ curriculum, says Anna Anund. The information made available can come in useful whenever the driver starts feeling drowsy at the wheel. It will be tactical information where the driver will be able to find out about effective things to do and the importance of doing something about being drowsy. Conceivably
One of VTI's projects is about ribbed grooves in the road surface, so called 'rumble strips' and is an example of possible measures to be taken in the road environment. Rumble strips make the car shudder and shake if the car starts to wander off the road. The driver will hopefully realise that she or he is about to drive off the road and take suitable action to correct this. Anna Anund thinks that quality assurance could be one of many other measures to be considered more. There should be a requirement that transport agreements include sufficient sleeping time for the truck drivers. – The problem of fatigue has to be regarded as a working conditions issue, and it may well be necessary to pass laws about driving time and rest periods, concludes Anna Anund.
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VTI
in the Fatigue Drama
PHOTO: PHOTODISC
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Help for Drowsy Motorists
VTI researchers Anna Anund and Björn Peters have been working with an EU project called AWAKE. The aim of the project that had its “final review” in Italy in September 2004 is to develop a system that can reliably detect worsening driver performance, caused by drowsiness or lack of concentration. The system which has been developed in AWAKE is based on SAVE, another EU project which was finalised in autumn 1998. – In SAVE, we produced a prototype of a system which detects problems in a driver’s situation for example, alcohol or drug abuse, drowsiness, health problems or long periods of lack of concentration. Of which all can ultimately lead to the risk of having an accident, says Björn Peters. As well as the AWAKE’s detection system there is also a module that assesses traffic risks and a warning system. Studies in VTI’s simulators
The AWAKE system’s detection ability is based on data collected from various behaviour measurements and different driving ability measurements. It gives different kinds of warnings depending on the level of calculated risk and how alert the driver is. Adjustments to the system have been made to suit various types of vehicles such as cars and lorries. – In the AWAKE project, VTI have been in charge of planning the evaluation studies and carrying out two experimental investigations in VTI’s simulators, says Anna Anund. Both R&D organisations and companies from the vehicle and electronics industries have been included in the project consortium 6
Hypovigilance Diagnosis Module
Traffic Risk Estimation Module
The Hypovigilance Diagnosis Module (HDM) diagnoses the driver’s wakefulness in real time. The diagnosis is made using an intelligent algorithm which works with data from different sensors (eye movements and grip on the steering wheel), and with data on how the driver is driving, for example, from side to side. The aim is to produce a system that is capable of diagnosing a tired driver with 90% accuracy with only 1% chance of a false alarm. It is set for driving on main roads. In order to attain this accuracy goal, the HDM calculations are based on the individual driver’s usual way of driving, which means when alert. A “smart card” is used to provide the system with information about who is driving. If the driver is unknown to the system the system collects new data about the person when she or he starts driving. The system learns how the driver drives and uses this as a starting point for any evaluation. HDM is made up of various subsystems, which deliver different independent diagnoses. The final diagnosis is made on three levels: • The driver is awake • The driver may be tired • The driver is tired.
In order to judge whether an ongoing traffic situation is risky or not, there is a module which uses data from a digital map, a positioning system and an anticollision radar. The output data from the module is used as input data for the HDM and for a warning system where ongoing traffic situations are evaluated. This takes place in a Traffic Risk Emulation Module (TRE). The traffic risk is evaluated on two levels: a general level and a specific level. Hierarchical Manager
Hierarchical Manager (HM) is the module that co-ordinates HDM and TRE and hosts the warning system. HM uses data from both HDM and TRE and evaluates what should be a suitable warning strategy in a given situation. Driver Warning System
The “Driving Warning System” (DWS) uses noise, light and movement in different combinations as warnings. The noise alert uses different kinds of warning sounds to get the driver’s attention and verbal messages to tell the driver why she or he is being given a warning. The visual warnings are located in the inside rear view mirror. In the rear view mirror, there is a unit with a smart card installed and buttons to start or stop the system. When the system decides the driver has to be warned using movement there is a vibrator alert located in the safety belt. More information about AWAKE can be found on the following website www.awake-eu.org/.
PHOTO: JOHNNY DAHLGREN
Article written by Tarja Magnusson. For more information contact Anna Anund, email: anna.anund@vti.se or Björn Peters, e-mail: bjorn.peters@vti.se.
AWAKE = System for Effective Assessment of Driver Vigilance and Warning According to Traffic Risk Estimation SAVE = System for Effective Assessment of Driver State and Vehicle Control in Emergency Situations
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VTI
Fatigue, Sleepiness and Reduced Alertness as Risk Factors in Driving
This is information from presentations and discussions from a workshop entitled “Fatigue, sleepiness, and reduced alertness as risk factors in driving”. The workshop was a part of the EU project IMMORTAL. The purpose of the project is to assess both chronic and acute driver impairments, and fatigue and drowsiness belong primarily among the acute impairments, although chronic impairment is also involved, as far as sleep disorders are concerned. Data
There are basically two types of data from drivers that are relevant as indicators of the scope of the problem. The first concerns the prevalence of sleepiness among drivers, and the incidence of actually falling asleep. The prevalence of fatigue without actually falling asleep is extremely difficult to assess, and no good estimates can be found. Concerning drivers who have actually fallen asleep, the estimates for a 12-month period range from 8 to 29 % of drivers. A rather conservative estimate then is that about one in ten drivers fall asleep at least once in a year. Barring the possibility of multiple occurrences for each driver, this implies an incidence of about one such event per 100 000 km. The second type of data relates directly to the role of fatigue and falling asleep as primary or contributing cause of accidents. Among those who report that they have fallen asleep, between 4 and 14 % (differing between studies)
PHOTO: TØI
Driver fatigue or falling asleep is recognized to be among the most important causative factors in road crashes, next to alcohol, speeding and inattention. A rather conservative estimate then is that about one in ten drivers fall asleep at least once in a year. Between 4 and 14 % report that the incident resulted in a crash.
It has been estimated that between 7 and 30 % of all personal injury crashes are caused by fatigue or sleep.
report that the incident resulted in a crash. It has been estimated that between 7 and 30 % of all personal injury crashes are caused by fatigue or sleep. And the evidence is clear that sleep- and fatiguerelated crashes are on the average more severe than other crashes. Vary with time of day
The risk of sleep-related crashes seems to vary with time of day, mirroring roughly the biologically based circadian variations in sleepiness and vigilance. This means that the risk shows a peak late at night or early in the morning, and a smaller peak in the afternoon. Although the risk of sleep and fatigue related crashes is larger during the night than during the day, the absolute number of such crashes is as high during the day as during the night, due to the larger exposure during daytime. Countermeasures should there-
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fore address the problem of falling asleep during daytime as well as during the night. The risk also tends to increase with prolonged driving, and the research evidence seems to give some support for current regulations of rest breaks during the drive as well as for total daily driving hours for professional drivers. More research is however needed to establish the optimal rest-work schedules. Widespread problem
Excessive sleepiness seems to be a widespread problem lying at the base of sleep- and fatigue-related crashes. This is primarily caused by “too much wakefulness”, as well as the circadian rhythm of sleepiness. In addition to those influences on daytime sleepiness, which everyone is subject to, some drivers are excessively sleepy because of some sleep disorder. The most prevalent sleep disorder is the 7
INSTITUTE OF TRANSPORT ECONOMICS (TØI)
obstructive sleep apnoea syndrome, which is a result of stopped breathing during sleep, resulting in poor quality of sleep and consequently excessive daytime sleepiness. This disorder affects as many as 4-5% of middle-aged men, who are the group with the highest prevalence. And then there is narcolepsy, or “intrinsic sleepiness”; patients with this condition are prone to fall asleep at any time. The prevalence is about 1 in 2000, and this group is clearly over-involved in crashes. Licensing procedures
Sleep disorders clearly have potential implications for licensing procedures. However, current methods are to a large extent dependent upon self-report instruments. This means that only individuals that present a sleep-related complaint to their doctor will be assessed with respect to implications for driving. And as long as the licensing requirements in several countries leave to the patients themselves to consider their suitability for driving in relation to sleepiness, there is no guarantee that even people with sleep disorders actually will refrain from driving. There are also objective methods for assessing sleepiness and the preconditions for falling asleep. By the use of such methods, important knowledge has been obtained regarding early signs, which may indicate a danger of falling asleep. Such knowledge can be used for information to drivers to pay attention to those signs, and stop driving when they occur. Technical devices
There is a growing body of research on technical devices to record the drivers’ vigilance states as well as their driving behaviour, with the purpose of giving a warning and/or interfere with the driving when the state of the driver is not compatible with the requirements from the traffic environment. An important future research need is field trials of such systems in order to assess their effect on driver behaviour and crash risk. A possible negative effect of in-car warning systems may be that driver’s use them to stay awake and drive for longer periods rather than stopping and have a nap; i.e. risk compensation by relying to much on the safety system. Further research 8
is needed to investigate how drivers adapt their driving to such systems, and what operational precautions should be taken to avoid risky behavioural adaptation. Drivers are often not motivated to take a break and have a nap when becoming fatigued or tired, but rather tend to engage in several activities in order to keep awake. Research has shown that most such activities (opening the window, increasing the volume of the radio, etc.) at best can postpone sleep for only a few minutes. The only effective countermeasure against sleepiness is sleep, preferably combined with a caffeine drink. A nap of at least 15 minutes is very effective and enables a driver to continue driving in an alert and vigilant condition for a considerable period. The nap should not exceed 30 minutes, because longer sleep may produce sleep inertia, from which the driver needs a certain time to recover. Drivers’ awareness
It is important to increase drivers’ awareness of the risks associated with driving when fatigued or sleepy, and about the effects of various countermeasures. The management of companies employing drivers have a special responsibility to take care that their employees are rested and fit and sufficiently aware of the risks, and also that their working schedules (especially for shift-workers) are compatible with the needs for rest and sleep. Educational programmes have been developed for helping both companies and individuals to manage fatigue in an adequate way. Concerning warning systems an important message should be that these systems do not reduce sleepiness, but they are only backup systems in case the driver is not sufficiently aware of the fatigue symptoms. Safe use as well as adequate training and information regarding new technical systems is part of the joint responsibility of employers and employees under the Occupational Safety and Health legislation regarding duty of care for a safe working place, including the vehicles used in employment. Monotonous roads
It has been assumed that a monotonous road and vehicle environment may facilitate
sleepiness. It is, however, somewhat controversial whether this can occur in rested drivers. It may be that monotony and boredom permit sleep in a driver who has insufficient sleep, but that it does not cause sleepiness. Some preliminary simulator studies of night driving have shown that road lighting has little effect on the development of sleepiness in general, but further research is needed on this issue, to find out to what extent environmental measures can contribute to the prevention of fatigue-related accidents. The idea that monotony and boredom permit sleep also implies on the other hand that stimulation may mask sleepiness. Even if one is very sleepy it is not difficult to stay awake while walking around, but once seated comfortably in the car one may fall asleep very quickly. Countermeasures
Countermeasures against fatigue and sleep-related accidents are of two types. They can either prevent drivers from falling asleep or developing fatigue while driving, or they can alert a driver or intervene with driving once a driver’s performance is impaired. Thus, there is both primary and secondary prevention of such accidents. Examples of primary prevention are information to raise driver’s awareness of early signs of fatigue or sleepiness, or warning systems detecting such signs. For professional drivers an additional countermeasure is the hoursof-service regulations. Rumble lines along the edge or centre of the road (profiled edgelines/centrelines) is an example of a secondary prevention that has proven very effective. Other examples are the incar systems to wake up a driver who has fallen asleep.
Title: Fatigue, sleepiness and reduced alertness as risk factors in driving Authors: Fridulv Sagberg, Paul Jackson, Hans-Peter Krüger, Alain Muzet, Adrian Williams TØI report 739/2004 Language: English language The report is available as a pdf file on: http://www.toi.no/ program/program.asp?id=935068
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INSTITUTE OF TRANSPORT ECONOMICS (TØI)
Summary:
Speed and Road Accidents: an Evaluation of the Power Model The relationship between speed and road safety is a controversial topic. In a study carried out at the Institute of Transport Economics, the relationship between speed and road safety has been evaluated. This study was designed to evaluate the Power Model of the relationship between speed and road safety. This model has been proposed by the Swedish road safety researcher Göran Nilsson. According to the Power Model, the effects of changes in speed on the number of accidents and the severity of injuries can be estimated by means of a set of power functions. A power function is a mathematical function that relates two variables to each other by raising values of one of the variables to a power in order to obtain values for the other variable. Any function in which a variable is raised to a certain exponent is called a power function (not to be mixed up with an exponential function, which is e (e = 2.71828) raised to an exponent). The Power Model describes the relationship between speed and road safety in terms of six equations. As an example, the equation referring to fatal accidents is: If speed is reduced from 100 km/h to 90 km/h, the ratio speed after/speed before equals 90/100 = 0.9. Raising 0.9 to a power of 4 gives + (0.9 x 0.9 x 0.9 x 0.9) 0.656. This means that the number of fatal accidents is estimated to go down to 0.656 times the initial number, corresponding to a reduction of 34.4 percent. The Power Model consists of one equation for fatalities, one for fatal and serious injuries and one for all injured road users. Moreover, there is one equation for fatal accidents, one for accidents involving fatal or serious injury, and one for all injury accidents. An exponent of 4 is proposed for fatal accidents, an exponent
If the speed is reduced from 100 km/h to 90 km/h the number of fatal accidents will be reduced with 34 percent, according to the Power Model.
of 3 for accidents involving fatal or serious injury, and an exponent of 2 for all injury accidents. For fatalities an exponent larger than 4, but smaller than 8 is proposed. For fatal and serious injuries, the exponent is between 3 and 6. For all injured road users, the exponent is between 2 and 4. Changes in the number of accidents or accident victims are modelled as a function of the relative change in the mean speed of traffic. The Power Model has been widely employed to estimate the expected effects of changes in speed. The objective of the research presented in this report was to
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evaluate the validity of the model by means of a systematic review and metaanalysis of relevant studies. Systematic literature search and metaanalysis
A systematic search for relevant studies was made by accessing the TRANSPORT literature database. “Speed and accidents” was used as search terms. A total of 1.469 entries were found. The computer search was supplemented by a manual search of selected scientific journals and previous reviews of the rela9
INSTITUTE OF TRANSPORT ECONOMICS (TØI)
Accident or injury severity Fatalities Seriously injured road user Slightly injured road user All injured road users (severity not stated) Fatal accidents Serious injury accidents Slight injury accidents All injury accidents (severity not stated) Property-damage-only accidents
Best estimate of exponent 4.5 3.0 1.5 2.7 3.6 2.4 1.2 2.0 1.0
95% confidence interval (4.1 (2.2 (1.0 (0.9 (2.4 (1.1 (0.1 (1.3 (0.2
– – – – – – – – –
4.9) 3.8) 2.0) 4.5) 4.8) 3.7) 2.3) 2.7) 1.8)
Source: TØI report 740/2004
tionship between speed and road safety. A total of 175 studies were identified as relevant. The results of these studies were summarised by means of a meta-analysis. To be included in the meta-analysis, a study had to state the relative change in speed and the relative change in the number of accidents or accident victims. 98 studies, containing 460 estimates of the effects of changes in speed were included in the meta-analysis. 77 studies identified as relevant could not be included in the meta-analysis, mostly because they did not report the information needed. Summary estimates of exponents were developed by means of meta-analysis. These analyses were performed by means of traditional techniques as well as techniques for meta-regression (multivariate models). Six models were developed. In addition, several versions of these models were employed in sensitivity analyses. The possible presence of publication bias was tested for by means of the trim-andfill technique. Results and interpretation of them
The results give clear support to the Power Model. The values of the exponents are not perfectly identical to those proposed by the Power Model, but they are close to them and exhibit a pattern that conforms to the Power Model. The Power Model, as stated, contains an element of inconsistency. To explain this, consider the following. The exponent for fatal accidents is 4. The exponent for accidents involving fatal or serious injury is 3. The exponent for all injury accidents, including fatal accidents, is 2. Thus, fatal accidents are represented by 10
an exponent of 4 when considered exclusively, but by an exponent of 3 when merged with serious injury accidents, and an exponent of 2 when merged with all injury accidents. The exponents of 4, 3 and 2 cannot all be true at the same time for the same category of accidents. The Power Model was therefore reformulated, so that the various levels of accident- or injury severity do not overlap, but are treated as mutually exclusive categories. The following exponents are the best estimates for the modified version of the Power Model: These results show that there is a strong statistical association between speed and road safety. As an example, it can be estimated that a 10 percent reduction in the mean speed of traffic will result in a 37.8 reduction of the number of fatalities. The results show the statistical relationship between speed and road safety. Correlation does not necessarily imply causation. Is there a causal relationship between changes in speed and changes in road safety? The report concludes that the relationship is indeed causal. This is based on the following arguments: 1. There is a very strong statistical relationship between speed and road safety. It is difficult to think of any other risk factor that has a more powerful impact on accidents or injuries than speed. 2. The statistical relationship between speed and road safety is very consistent. When speed goes down, the number of accidents or injured road users also goes down in 95% of the cases. When speed goes up, the number of accidents or injured road users goes up in 71% of the cases. While it may to
some extent be possible to offset the impacts of higher speed by introducing other road safety measures, a reduction in speed will almost always improve road safety. 3. The causal direction between speed and road safety is clear. Most of the evidence reviewed in this report comes from before-and-after studies, in which there can be no doubt about the fact that the cause comes before the effect in time. 4. The relationship between speed and road safety holds up when potentially confounding factors are controlled for. There is no evidence of a weaker relationship between speed and road safety in well-controlled studies than in less well-controlled studies. 5. There is a clear dose-response relationship between changes in speed and changes in road safety. The larger the change in speed, the larger the impact on accidents or accident victims. 6. The relationship between speed and road safety appears to hold universally and is not influenced by, for example, the country in which it has been evaluated, when it was evaluated or the type of traffic environment in which it was evaluated. 7. The relationship between speed and road safety can be explained in terms of elementary laws of physics. These laws of physics determine the stopping distance of a vehicle and the amount of energy released when an impact occurs. It is concluded that there is a law-like and causal relationship between speed and road safety. This relationship is adequately described by means of the Power Model. Some limitations of the study
The study has a number of limitations. The most important of these can be summarised as follows: 1. A fairly high proportion of the relevant studies, 77 out of 175, could not be included in the meta-analysis. An assessment has been made of whether exclusion of these studies has influenced the results of the study. It is concluded that exclusion of these studies from the meta-analysis is unlikely to have
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INSTITUTE OF TRANSPORT ECONOMICS (TĂ˜I)
affected its results materially. 2. There is a possibility of publication bias in the data, meaning that studies that are regarded as useless, or whose findings are difficult to interpret, are less likely to be published than other studies. A formal tests for publication bias was conducted and no evidence of it was found. 3. The results may to some extent reflect the effects of other road safety measures, not just changes in speed. This is true as far as individual studies are concerned. It is, however, not true as far as the results of the meta-analyses are concerned. In these studies, the effects of other road safety measures were controlled for statistically by means of multivariate analyses. Hence, the summary estimates of power show the effects of speed only. 4. Data concerning speed and/or accidents can be unreliable. This is obviously correct. However, the impact of unreliable data is always to attenuate statistical relationships, never to reinforce them. It is therefore highly likely that the true effects of speed on road safety are underestimated in this study. 5. A number of studies contain multiple estimates of effect. If these estimates are statistically dependent on each
other, variance is reduced and a spuriously strong relationship between speed and road safety can be found. The variance of study findings was assessed, and no evidence of any withinstudy statistical dependency was found. 6.The study does not state what the relationship between speed and accidents is for specific types of accidents or in specific types of traffic environment. Unfortunately, the data did not allow the relationship between speed and accidents to be estimated for specific types of accidents. As far as different types of traffic environment are concerned, the analyses gave no indication of any differences with respect to the impacts of speed on road safety. 7. The study has evaluated the Power Model only. Very many other models can be imagined to summarise the relationship between speed and road safety. Only two alternative models have been examined. One of these is a linear model, according to which it is the absolute change in speed, not the relative change, that produces changes in road safety. The other model is a logistic model, according to which the effects of changes in speed depend on the initial level of speed. The linear
If the government wants to develop a road transport system in which nobody is killed or permanently injured, speed is the most important factor to regulate. NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
model is highly implausible. The logistic model is somewhat more plausible, but the data did not permit it to be tested in a sufficiently stringent manner. It is concluded that the Power Model is to be preferred to other models because of its generality and simplicity. The overall conclusion is that the limitations of the study are unlikely to have influenced its findings. Practical implications
Speed has been found to have a very large effect on road safety, probably larger than any other known risk factor. Speed is a risk factor for absolutely all accidents, ranging from the smallest fender-bender to fatal accidents. The effect of speed is greater for serious injury accidents and fatal accidents than for property-damageonly accidents. If government wants to develop a road transport system in which nobody is killed or permanently injured, speed is the most important factor to regulate. The report argues that driver speed choice may not always be perfectly rational; hence, a legitimate basis exists for limiting the freedom of choice with respect to speed. The need for such regulation is very widely recognised, as nearly all motorised countries have an extensive system of speed limits and a programme of enforcement. Speed limits and their enforcement are very important road safety measures.
Title: Speed and road accidents: an evaluation of the Power Model Authors: Rune Elvik, Peter Christensen, Astrid Helene Amundsen Series: TĂ˜I report no: 740/2004 Language: English, www.toi.no/program/program.asp ?id=976303
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INSTITUTE OF TRANSPORT ECONOMICS (TØI)
Changes of speed limits:
Effects on Speed and Accidents
In the autumn of 2001, speed limits were lowered from 80 km/h to 70 km/h on 247 hazardous road sections in Norway. On 47 hazardous road sections the speed limits were lowered from 90 km/h to 80 km/h. These road sections had been identified as having a expected injury severity density (based on accident costs pr km), i.e. a high number of fatal or serious injury accidents per kilometre of road. Effects were evaluated by means of a before-and-after study. The study controlled for long-term trends in accident occurrence by applying two comparison groups defined as follows: 1. Comparison group 1 consisted of roads that retained the original speed limit of 80 km/h (alternativly 90 km/h) 2. Comparison group 2 consisted of all public roads in Norway (minus those that had the speed limit lowered). Data on changes in speed have been taken from permanent traffic monitoring stations operated by the Public Roads Administration. There are more than 200 of these stations in Norway, and data from 29 of them have been used. Effect on speed
The net reduction in mean speed attributable to the lowering of the speed limit is estimated to between 4.1 km/h and minimum 2.1 km/h on roads that had a speed limit of 80 km/h before treatment. The corresponding net reduction in mean speed on 90 km/h roads can be estimated to between 2.8 and 1.6 km/h. 12
Effects on accidents and injured road users
Table 1 summarises estimated effects on accidents and injured road users of the changes in speed limits. Effects are stated as percentage changes in the number of accidents or injured road users. On roads where the speed limit was lowered from 80 km/h to 70 km/h, there has been a reduction of both accidents and the number of injured road users. The size of the reduction attributed to the change in speed limit, labelled net change and shown in two columns in Table 1, differs slightly depending on whether comparison group 1 or comparison group 2 is used to account for long-term trends. By and large, however, the two sets of estimates are quite close. The largest reduction is found for fatalities and critical injuries. On roads where the speed limit was lowered from 90 km/h to 80 km/h, the findings are more difficult to interpret. There has apparently been an increase in both the number of accidents, the number Table 1: Effects on accidents and injured road users of changes in speed limits. Percentage changes Net effect based on comparison group 1
Net effect based on comparison group 2
Roads where speed limit was lowered from 80 to 70 km/h Accidents Fatalities Critically injured Seriously injured Slightly injured
-16 -42 -78 -23 -10
-14 -25 -77 -12 -6
Roads where speed limit was lowered from 90 to 80 km/h Accidents Fatalities Critically injured Seriously injured Slightly injured
50 -22 -29 36 64
Source: TØI report 729/2004
41 29 13 78 45
PHOTO: TØI
Lowering the speed limit from 80 km/h to 70 km/h on hazardous road sections in Norway, successfully reduced the number of accidents with 14 to 16 percent. The reduction in injured road users is largest for fatalities and critical injuries. This is the conclusion in a study carried out by Institute of Transport Economics (TØI). The effects of lowering the speed limit from 90 km/h to 80 km/h are less clear.
of fatalities and the number of seriously or slightly injured road users. The findings do not make much sense, and are strongly influenced by the choice of comparison group. Neither of the two comparison groups used can be considered ideal. Conclusions
It is concluded that lowering the speed limit from 80 km/h to 70 km/h on hazardous road sections in Norway has successfully reduced both speed, the number of injury accidents and the number of injured road users. The reduction is largest for fatalities and critical injuries. The numbers are significant (5% level). The effects of lowering the speed limit from 90 km/h to 80 km/h are less clear. A reduction in speed has been found, but it was smaller than the reduction associated with lowering the speed limit from 80 km/h to 70 km/h. Overall, no reduction in the number of accidents or injured road users has been found. Numbers not significant.
Title: Changes of speed limits: Effects on speed and accidents Author(s): Arild Ragnøy Series: TØI report 729/2004 Language: Norwegian with English summary. The summary is available on http://www.toi.no/program/ program.asp?id=819265
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DANISH ROAD DIRECTORATE (DRD)
PHOTO: DRD
NordFoU – A New Nordic Road Research Initiative
An example of disturbing reflections of light on a wet road surface.
Article specially written for Nordic Road and Transport Research by Maria Lønsmand Meiner (mm@vd.dk), Danish Road Directorate.
The Nordic road administrations have set up a new administrative platform, NordFoU, to facilitate research projects on an Inter-Nordic basis. The idea is twofold: to get more research value for
money and to secure that the relatively small research units in the Nordic countries can have access to a larger market and thereby to strengthen their financial possibilities to maintain their specialisation. The official agreement for the NordFoU was signed by the Road Directors at their meeting in Helsinki, Finland in December 2004. Two research projects have been launched immediately and further projects are under preparation.
NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
In order to meet the future challenges of the road network, there is an increasing demand for the national road administrations to ensure, that new and updated knowledge concerning mobility, safety, sustainability, design and production etc is at hand when needed for developing the road network and to keep it well maintained. In order to achieve this, the Nordic road administrations participate in a variety of research projects on European level, such as through FEHRL, ERTRAC and ERA-NET Road. 13
DANISH ROAD DIRECTORATE (DRD)
However, it is clear, that there is a potential for obtaining further, new research results in co-operation with other Nordic countries. The national road administrations in Iceland, Norway, Sweden, Finland and Denmark have therefore decided to join forces to establish a new common research initiative entitled NordFoU. The five Road Directors officially launched the NordFoU initiative on 10 December 2004 in Helsinki, Finland with the mutual signing of a common framework agreement. Over a long period of time there has existed a wide range of bilateral research cooperation between the Nordic countries. The NordFoU initiative, however, aims especially at strengthening, promoting and organising this research cooperation in a more formalized manner. Within NordFoU, cooperation can take many different forms. It will always involve at least two countries depending on what new knowledge is needed in each of the countries. A NordFoU project is thus initiated, when two or more partner countries agree on the scope of the research and on joint funding of the project. A project will typically be realized with the participation of private consultants and/or universities from the Nordic countries. The NordFoU initiative is organized with a Steering Group that approves proposals for potential joint research projects, after they have been analysed by a Preparatory Group, so that the progress of the project can be coordinated and prioritised as required. The Steering Group and the Preparatory Group are chaired by rotation, so that the work of hosting and organising the meetings is undertaken by the road authority which chairs the meeting. The partner countries in NordFoU have also agreed on a procedural model in order to lay down principles on how the future cooperation can be brought about and carried out, as this will make the scope of the project progress and results predictable and clear. Generally the cooperation relies on mutual interest and is very non-bureaucratic. The NordFoU Steering Group has so far agreed on four joint projects, of which two projects are already in progress, and two are being planned in more details. 14
Below is given a short description of each of the projects. Nord2000 Road Engineering Model; The purpose of this project is to implement a validated engineering model for road noise mapping and prediction. The model takes into account recent source data and regionally determined all-year weather conditions, based on the common Nordic Nord2000 reference noise model. The output of the project is expected to be published as a Nord2000 Road user guide, including guidance for calculation and implementation, both on the Internet and in paper form. The project responsibility rests with Denmark (the Danish Road Directorate), which also has the project leadership. Finland, Iceland, Norway and Sweden are all participating partners. Disturbance from lighting during road construction work at night; In order to avoid disturbing traffic during daytime, road construction work is increasingly being carried out in the evening and night. This often results in a complex environment, with a wide range of distracting factors, such as temporary road markings, different light signals and projectors which can be very distracting and disturbing to drivers. Especially the use of projectors can, in very unfortunate circumstances, cause momentary blinding of the drivers. The purpose of this project is to analyze how road construction work during the night can be carried out with the least possible disturbance to the drivers. The project will concentrate on four primary topics; the use of yellow light warning signals, the illumination of workplaces in relation to the construction site, other different sources of disturbing light from the road side and finally the disturbance caused by reflections of light on a wet road surface. The project responsibility rests with Sweden (the Swedish Road Administration), which also has the project leadership. Denmark, Finland and Norway are participating partners. Deterioration models for flexible pavements; the aim of the project is to develop a joint Nordic model that enables the road administrator to assess the wear of roads, so that existing models in pavement management systems may be upgraded with this new knowledge. In
this way, the condition of the road surface - measured as a function of a number of parameters, such as time, traffic volume and climate - can be described in a more detailed way, than is possible today. This will eventually lead to improved tools for the planning of construction and maintenance activities. The project responsibility rests with Norway (the Norwegian Public Road Administration), which at present has the project leadership. Denmark is the participating partner. Life Cycle Analyses for Bridge Management Systems; The aim of the project is to create appropriate information tools related to a bridge and its life cycle for designers, contractors and bridge owners. The purpose is to optimise all aspects of a bridge, such as functionality, techniques, economics and aesthetics in the lifetime of a bridge. One of the main goals of this project is to bring the principle of sustainability into practice in bridge engineering. Also, the project will seek to produce measuring methods for comparing and evaluating different items to judge the life cycle of a bridge. The project responsibility rests with Finland (FinnRa), and the project leadership will be held by Helsinki University of Technology. Norway and Denmark are participating partners. While the two first projects are already underway, the two latter are still in the planning phase, which means that the current content of the projects does not necessarily correspond to what will finally be decided. There will be a continuous preparation of new possible joint projects for the Steering Group to decide on. Even in the relatively short time, that NordFoU has been working, it has become clear, that the Nordic Road Administrations have a lot of common challenges and questions, that need to be properly addressed, and the most efficient way of doing that, is to do it jointly.
NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
DANISH ROAD DIRECTORATE (DRD)
Traffic Management and Noise Reductions Article specially written for Nordic Road & Transport Research by: • Hans Bendtsen, Road Directorate/ Danish Road Institute (DRI), Denmark. • Jürgen Haberl, Vienna University of Technology (TUW), Austria. • Ulf Sandberg, Swedish National Road and Transport Research Institute (VTI), Sweden. • Greg Watts, Transportation Research Laboratory (TRL), United Kingdom.
the residents and more agreeable to shop and walk in for shoppers and other people. The term “traffic management” can be described as an application of different strategies and measures to change the flow of traffic on roads either to reduce the speed of vehicles passing by and/or to reduce the traffic volume itself. This will all have an effect on the environmental noise caused by vehicles. Modelling noise
This article presents a new handbook on local road traffic noise abatement in cities produced by the Road Directorate and the Environmental Protection Agency in Denmark. Noise abatement is traditionally quite expensive. New ideas to integrate noise abatement in ongoing activities like road and building maintenance, urban development and renewal are presented together with alternative ways to organise and finance noise abatement.
The use of new emission data for the Nordic Noise Prediction method shows that for urban driving at speeds in the range of 30 to 60 km/h a speed reduction of 10 km/h for light vehicles reduces the
noise by up to 2 to 4 dB depending on the starting point. For heavy vehicles the reduction potential is 2 to 3 dB. For speed reductions of 10 km/h in the speed range from 110 to 60 km/h the noise reduction will be about 1 to 2 dB for roads with 10 % heavy vehicles. But this is not the entire truth; as the discussion below will indicate. In some cases traffic management is used to reduce the amount of traffic on a road and/or to reduce the percentage of heavy vehicles. A 10 % reduction of traffic only leads to a 0.5 dB noise decrease, whereas a 50 % reduction decreases noise by 3 dB. On a road with 10 % heavy vehicles the noise will be reduced by 1 to 2 dB if all the heavy vehicles are removed.
NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
PHOTO: DRD
Traffic management measures in order to reduce speed and improve traffic safety are used on many European roads. In this article the consequences for noise reduction is investigated and the possibilities to integrate the use of noise reducing pavements and traffic management are evaluated. The article is based on work carried out in the SILVIA project. Traffic management measures such as environmentally adapted “through” roads, 30 km/h zones, road humps, roundabouts, restrictions on traffic in special time periods, speed control etc, are used on many urban roads in Europe. These measures are usually applied to improve traffic safety, typically by reducing the speed, and to “calm” residential areas from the environmental impact caused by traffic in order to make the areas more pleasant to live in for 15
DANISH ROAD DIRECTORATE (DRD)
The driving pattern also has an influence on noise levels, although uneven driving patterns usually do not dominate under normal driving conditions. At moderate accelerations the noise can increase by up to 2 dB (in comparison to constant driving speed) where such accelerations occur (which may be on rather limited locations) depending on the mix of vehicles. This is a little less than the reduction achieved by a speed reduction of 10 km/h. It is therefore important to design speed reduction measures in such a way as to avoid accelerations and decelerations as much as possible and to ensure that the accelerations do not occur at or near the position of dwellings or other noise-sensitive areas.
Traffic management measure
Potential noise reduction (LAeq)
Traffic calming / Environmentally adapted through roads
Up to 4 dB
30 km/h zone
Up to 2 dB
Roundabouts
Up to 4 dB
Round-top/circle-top road humps
Up to 2 dB
Flat-top humps
Up to 6 dB increase
Narrow speed cushions
Up to 1 dB increase
Night time restrictions on heavy vehicles
Up to 7 dB at night time
Speed limits combined with signs about noise disturbance
1 – 4 dB
Rumble strips of thermoplastic
Up to 4 dB noise increase
Rumble areas of paving stones
Up to 3 dB noise increase
Rumble wave devices
0 dB
Traffic management examples
A comprehensive European literature survey has been conducted in order to find and compile existing relevant knowledge on relations between traffic management and noise. In the table the results of the literature survey are summarised. The effect on noise is based on estimates for traffic with up to approximately 10 % of heavy vehicles. The effect on noise of the different traffic management measures depends very much on the precise design and implementation of the measures, as well as on how they are accepted by the drivers. Generally, it can be concluded that reductions in average noise levels (LAeq) of up to 4 dB can sometimes be achieved but in special situations even higher reductions may be reached, as well as no reduction at all may occur in some cases. Some speed reducing measures might increase noise like rumble areas and paving stones. Vertical deflections such as humps and cushions can reduce the average levels due to significant speed reductions but the maximum levels can increase due to body rattle noise produced, as some vehicles (especially empty container lorries) negotiate the deflection. The actual reduction in the average level will depend critically on the percentage of heavy vehicles in the traffic stream. Observations and recommendations
The following general observations and 16
recommendations in relation to noise can be drawn: 1. Speed reductions reduce noise. 2. However, the noise from heavy vehicles can in some cases increase due to shift of gear, rapid speed changes and body rattle noises. 3. In order to achieve a reduced speed it is normally not enough just to install speed limit signs. It is also necessary to redesign and rebuild the road in order that the physical layout matches the intended speed. 4. Visual speed reducers are often effective in reducing noise. 5. It is important to achieve as smooth a driving pattern as possible. 6. It is important to minimise uneven driving patterns. This can be done by having appropriate distances between speed reducers. 7. It is important to achieve driving patterns where the vehicles are not brought to a complete stop as this generates more noise from decelerations and accelerations. 8. Speed reducers which displace the vehicles sideways are often effective in reducing noise especially in the case of heavy vehicles. 9. Speed reducers which change the vertical height of parts of a road (like some types of road humps) can be problematic in relation to noise, especially for heavy vehicles, where
body rattle noises can produce large peaks in noise levels as these vehicles cross the vertical deflections. 10. The use of rumble areas, for example with paving stones, increases noise. 11. There are reports of cases with increased perceived annoyance even though the average noise level has decreased. 12. There are reports on increases in the perceived noise annoyance because of impulse-like noise, rattling in the bodywork or cargo of heavy vehicles, as well as short-time changes in the sound level and frequency caused by gear shifting or changing in engine revolutions due to acceleration or braking of a vehicle. 13. Speed reducers, which change the vertical height of parts of a road, may produce perceptible levels of vibrations in nearby houses. This depends on the type of ground condition and distance from the vertical deflection to the nearest house foundations. Serious annoyance has been reported especially where houses are close to road humps built on soft ground such as peat soils and alluvium deposits. In a Danish report it has been suggested that 5 dB should be added as a “penalty” to the actual noise level if impulsive noise or similar is occurring (for example where rumble areas/strips or paving stones are used) to compensate for the
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DANISH ROAD DIRECTORATE (DRD)
increased perceived annoyance. It must, generally, be concluded that more research is needed to investigate and quantify the effect of impulsive noise from road traffic, especially in relation to certain types of speed reducers. A general recommendation could be, on the background of existing knowledge, to place speed reducers which change the vertical height of parts of a road and/or include rumble areas at a distance as long as possible from houses where people are living, but this is easier said than done since it is exactly at such places where the maximum speed reductions (for noise reduction purposes) are needed.
roads especially constructed to reduce speed. Speed reducers which displace the vehicles to the left or right may be problematic for the durability of porous pavements, because this will make the vehicles drive in curves for short distances. But other types of noise reducing pavements can be used in such cases. In other parts of the SILVIA project the noise reducing effect of different pavement types are documented. On urban roads with speeds in the range from 40 to 60 km/h noise reductions of 1 to 4 dB can be achieved by using for example noise reducing thin layers or porous pavements. At higher speeds the noise reducing potential for these pavements may be up to 6 dB or even more. This noise reduction is of the same magnitude as or higher than the reduction which can normally be achieved by traffic management measures. Noise reducing pavements and traffic management measures may influence the frequency distribution of road traffic noise in different ways, and this can have an influence on the total noise reduction. The effect of the two types of noise reduction are not exactly additional; in particular at lower speeds. But it is therefore generally on urban roads possible to obtain noise reductions of 3 to 8 dB by combining the use of noise reducing pavements and traffic management measures. On highways with high speeds the potential for noise reduction may be up to 10 dB or even more. Generally, noise reducing pavements have a better reduction effect on noise from light vehicles than on noise from heavy vehicles. This means that if a traffic management measure such as an "environmentally adapted" street or a 30 km/h zone has an effect in reducing the percentage of heavy vehicles the beneficial effects of the noise reducing pavements will be increased.
Combination with noise reducing pavements
It is obvious that it can be a good idea to combine traffic management measures and the use of noise reducing pavements in noise abatement schemes. Generally there does not seem to be any technical argument for not combining these measures of noise abatement. However, it must be noted that porous pavements can be damaged in bends, junctions and roundabouts where tangential forces in the tyre/road interface are relatively high. This must be taken into consideration when applying porous pavements on
PHOTO: DRD
Conclusions
To achieve a reduction in noise by limitations of the traffic volume requires substantial reductions in traffic: However, quite significant effects are possible if heavy vehicles are prohibited. Speed reductions in the range down to about 30 km/h are effective in reducing
NORDIC ROAD & TRANSPORT RESEARCH NO. 1 2005
noise emission of light vehicles. In most cases, speed reduction measures have resulted in a measured reduction of noise emission. However, in achieving such speed reductions effectively, it is often necessary to use measures which themselves increase noise emission and/or annoyance. The more uneven driving pattern may somewhat increase noise annoyance. Rattling and other body noise from passing of vertical deflecting devices, which often occurs for heavy vehicles, may cause serious annoyance. Therefore, the net effect on noise annoyance of such speed reductions is not clear-cut; both failure and successes have been recorded. With very careful design of speed reducing devices, especially in the location of them, there is nevertheless a certain potential for reduced noise annoyance by such measures. Real effective solutions may only be provided by the intelligent speed adaptation systems that might be implemented in the future. Noise-reducing pavements have a potential for noise reduction too. This potential is at least as high as that of speed-reducing measures. Also in this case, significant heavy vehicle traffic limits the achievable noise reductions. There are limitations as to the durability of certain low-noise pavements; in particular in environments where significant tangential tyre/road forces occur. Therefore, low noise pavements in areas subject to traffic management measures must also be selected with greatest care. The combination of speed-reducing measures and low-noise pavements is usually beneficial, although noise reductions from each measure are not exactly additional; in particular at lower speeds. The work described in this article is carried out by the authors in the framework of SILVIA a project supported by the European Commission. The work is documented in the report “Traffic management and noise reducing pavements Recommendations on additional noise reducing measures� which is published by the Danish Road Directorate/Danish Road Institute. The report can be downloaded from: www.roadinstitute.dk. Information about the SILVIA project can be obtained from: www.trl.co.uk/silvia/ 17
DANISH ROAD DIRECTORATE (DRD)
PHOTO: DRD
New Ideas to Reduce Road Traffic Noise in Cities
Article specially written by for Nordic Road and Transport Research by: Senior Researcher, Hans Bendtsen, Road Directorate, Danish Road Institute Graduate Engineer, Lene Nøhr Michelsen, Road Directorate, Planning Department Cand. tech. soc., Brian Kristensen, Industry & Transport, Danish Environmental Protection Agency
Nowadays, when constructing new buildings or roads, special consideration is given to noise. A new national noise map indicates that 28% of Danish homes are exposed to noise levels that exceed the threshold value of 55dB, and that noise problems are concentrated in cities. Road traffic noise affects people in different manners such as sleeping disorders, stress and it also troubles learning. 18
Furthermore, new studies show that noise can contribute to an increased risk of cardio-vascular disease. The effects of noise are also of economic nature in that they influence property values in noise polluted areas. Furthermore, health related issues caused by noise also incur costs. The socio-economic costs related to road traffic noise have been calculated to amount to between 5.9 and 8.7 billion DKK annually in Denmark. [1] Road noise strategy
It is a difficult task to reduce road noise in cities. It is therefore necessary to find new ways and means to reduce the effects of road noise. With the passing of EU directive 2002/49 [2] it can be expected that in the future there will be an increased focus on noise and its effects. This article is based on a catalogue of ideas that will be presented by the Danish Environmental Protection Agency and
the Road Directorate in the autumn of 2004. It is the aim to present visionary ideas and proposals to help local authorities and private participants to reduce the negative effects of road traffic noise in urban areas and noise polluted residential areas. The catalogue is a collection of new alternative ideas and well known, proven methods that can be combined in a new manner. Special emphasis has been placed on methods that are not costly for public authorities. The starting point of the report is a presentation of noise problems experienced in daily life situations in residential areas, illustrated by both Danish and foreign examples. Work with the idea catalogue is a follow-up to the “Strategy for Limiting Road Noise Traffic” that was published in November 2003 [1]. Local efforts necessary
Changes in the noise levels due to the
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DANISH ROAD DIRECTORATE (DRD)
expected general increase in traffic in the period 2001 – 2020 and the implementation of EU legislation for noise emissions from new cars and new tyres are limited. A general decrease of 0.6 dB is expected in city streets, where the main part of the exposed homes are located. Along country roads and motorways a slight increase of 0.2 to 0.7 dB is expected in the period until 2020. Nothing indicates therefore, that improved car technology within the foreseeable future will solve noise problems. It is however, necessary to have a targeted local effort if something is to be done to alleviate noise problems. Economic aspects tend to limit the authorities in their efforts and in some cases might even deter them from even addressing the noise issue. The City without noise pollution
In planning tasks, it is common to base work in a set of goals and to analyse which means and methods can be applied to meet the goals. Technical, economic and political possibilities and limitations are important factors in the preparation of plans that should realistically be able to be executed. In the idea catalogue several differentiated noise criteria are presented with a view to “bring to life” the term “The City without Noise Pollution” in such a manner that takes the city’s existing physical and functional structures into consideration. This is done on the basis of noise criteria that have been compiled by WHO and on the basis of the noise criteria applied in Denmark when building new homes in existing residential areas. It is proposed that cities be divided into four noise zones, each to be assigned specific noise level requirements: • Zone A: quiet areas, where noise levels may not exceed 45 dB • Zone B: residential areas with reasonable noise conditions, where noise levels may not exceed 55 dB • Zone C: noise polluted central areas, where noise levels may not exceed 65dB • Zone D: heavily noise polluted areas that are typically located near main roads and intersections
The same noise level requirements should also be applicable to public institutions etc. that are located in these areas. To compensate for the high noise levels that are expected to be experienced outdoors in zones C and D, there should also be public open space areas such as parks, playgrounds or other similar areas that have relatively low noise levels. The four noise zones are intended to be used as a tool for taking noise conditions into consideration when planning in cities. They can also be applied in connection with municipal planning or when drawing up noise reduction plans. The tool will be able to place all residential areas in a city in one of the four noise zones based on the actual noise conditions in the respective areas. This will result in noise level guidelines for all residential areas. If there is a local wish for a special effort to reduce noise, individual guidelines and a prioritized plan can be drawn up using different means. The division of the noise zones will shed light on the noise conditions in a city. It can form the framework for noise level identification in all areas of a city, in such a manner that the noise levels can be objective parameters when choosing an area in which to live. It can be used by citizens to examine noise conditions before choosing i.e. day-care for children, schools or work place. Furthermore, defining noise zones will ensure that conditions in zones A and B will not be negatively affected by permitting activities that will increase the noise levels in these areas. Methods
There is no single method that can remove all noise problems in a city. It is necessary to work on several fronts and to employ several different methods in order to change the trend towards a city without noise problems. This task is formidable and the technical methods alone will not be able to achieve the goals. It is necessary to address the noise issue on several different levels: [3] 1. At the source: this covers vehicles, pavements, traffic and speed. When noise is reduced at the source it has an
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effect on all buildings and open space areas that are affected by the noise on a given road section. A noise reduction on pavements and bicycle paths along the road will also be experienced, an improvement for pedestrians and cyclists 2. At the area of distribution: in the form of noise barriers and such. By using noise barriers, a noise reduction will be experienced in buildings and open space areas that are behind the barriers, but not for the areas in front of the barriers. 3. At the receiving end: in the form of façade insulation and local barriers. Façade insulation is limited to the noise level inside, whereas the noise level outside remains unaffected. A series of methods can be applied to reduce noise such as noise reducing pavements, traffic diversion, speed reductions, limiting heavy traffic access at night, vegetation and façade insulation to name a few. Environmental zones with speed limits can also be used to reduce noise levels. Organisation
Often nothing is done to reduce noise problems, perhaps due to the fact that there is no clear “owner” of the problem or there is no organisation that can take initiatives for improvements. Also, problems might seem overwhelming; there could be a lack of useful ideas or alternatives to finance the proposed activities; this may result in nothing being done. However, it is very important to support and stimulate positive development, even though the barriers seem insurmountable and the results to start with are very limited. To aid initiating and carrying out noise related work at municipal authorities, a special noise secretariat could be established whose employees would mainly deal with planning, initiating and managing local efforts. A concerted effort of the different municipal departments and other affected parties such as private citizens, owner and tenants’ associations and the business community is advisable. A municipal authority is a large organisation that continuously plans and implements activities in the construction, running and maintenance fields. It could 19
DANISH ROAD DIRECTORATE (DRD)
an important role as an “idea bank”, initiative taker and coordinator. In this forum one could gather citizens affected by noise and present them with technical solutions as well as helping them to organise noise reducing efforts that could be achieved and paid for, either in part or fully, by the citizens themselves. The municipal efforts could consist of organisation and coordination with a view to activating the assets and resources available amongst the citizens, and also to partake in the carrying out of certain tasks. Furthermore, one could examine the possibility of sharing the costs of certain activities.
planned measures. There is a number of indications and examples of how knowledge of noise can be disseminated and how citizens can actively become involved in working with reducing noise [6]. This article is based on the report: " Nye veje til støjbekæmpelse i byer - et idekatalog" (New methods for noise abatement in urban areas - a catalogue of ideas). Report no 295 from 2004 published by the Road Directorate (www.vd.dk) and the Environmental Protection Agency (www.mst.dk) The report is written in Danish. The report can be downloaded from: http:// www.vejdirektoratet.dk/publikationer/ VDrap295/index.htm.
PHOTO: DRD
Financing
be considered a municipal goal that noise issues become an integral part in all relevant activities such as road maintenance, building maintenance and renovation of open space areas and parks. City planning and possible adjustments within existing urban areas are tasks that are handled by the municipal authorities. Noise is an important parameter that is taken into consideration when building new housing areas. However, it would be also be useful to include noise as a parameter when addressing issues such as rebuilding and expanding housing areas. A starting point could be drawing up a set of municipal goals for noise related issues in existing urban areas. Assets
There is a need to activate as many assets as possible for the work to reduce noise. A municipal authority can play an important role in relation to private citizens and the business community. Research shows that in certain cases private citizens are willing to participate in funding noise reducing measures [4]. It is important to inform citizens of the technical and economic possibilities as these are not always common knowledge. A municipal noise secretariat can play 20
There are several examples from both Denmark and abroad that show how noise reducing projects have been financed [5]. House owners can implement noise reducing measures at their own homes at their own cost. A rise in property value as a result of the noise reducing measures can be the reason that some owners finance these measures themselves. Depending on the current tax situation, increased property values mean that the both the state and the municipality receive increased taxes, that can again be reinvested in other noise reducing projects. In apartment buildings noise reduction can be achieved by changing to special noise insulating windows that can be financed over the annual maintenance budget; this could equally well finance other noise reducing projects. Dissemination
In connection with noise reducing projects that are planned in cities, it is recommended to involve those citizens that will be affected by these projects. This will contribute to giving the citizens influence on which solutions will be chosen and to give them a realistic picture of which level of noise reduction to expect. Citizens can become actively involved and in some cases even be joint partners in the planned projects. A possible spinoff of becoming actively involved could be that citizens become moti-vated to implement further measures that can improve the effect and the quality of the
References 1. Proposal of a strategy to reduce road noise traffic. Road Noise Group: Danish Environmental Protection Agency, Ministry of Finance, Ministry of Transport, Ministry of the Interior and Health, Ministry of Justice, Ministry of Economic and Business Affairs, November 2003. www.mst.dk 2. EU-Directive 2002/49/EC of the European Parliament and of the Council of 25 June 2002 relating to the assessment and management of environmental noise. 3. Road Traffic and Noise – the Basics. Report 146, 1998, Road Directorate, www.vd.dk 4. Traffic Noise Annoyance. A Survey in Aarhus, Odense and Randers. Hans Bendtsen, Lars Ellebjerg Larsen, Bo Mikkelsen. Report 5, 2002. Danish Transport Research Institute, www.dtf.dk 5. Noise Reduction Efforts in Germany and Switzerland – A Report of a Study Tour, Note 73, 2000, Road Directorate 6. Dissemination of Noise – A Challenge. Lene Nøhr Michelsen et.al. Danish Road Magazine, 4-2003 www.vejtid.dk
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
NORWEGIAN PUBLIC ROADS ADMINISTRATION (NPRA)
The Impacts of Road Salt and Other Highway Pollution on the Water Quality and Circulation Conditions in Lake Padderudvann Authors: Per Johan Færøvig, University of Oslo (p.j.farovig@bio.uio.no) Torleif Bækken, Norwegian Institute of Water Research (NIVA) (torleif.baekken@niva.no) Torbjørn Jørgensen, Norwegian Public Roads Administration (torbjorn.jorgensen@vegvesen.no)
Lake Padderudvann is situated near a four-lane highway (E18) in the municipality of Asker. It is highly exposed to pollution from traffic and road salting. In 1947-1948 and 1966-1967, two investigations of the lake were carried out by the University of Oslo. In 1980-1984 and 1991-1992, the Norwegian Institute of Water Research (NIVA) carried out two extensive investigations of the lake. Information was collected on the types of pollution from the road, the acute detrimental effects on plant and animal life and the possible long-term effects. These studies show that road salting of E18 during wintertime has resulted in increased concentrations of salt in the lake water. Every winter ca 24 tons of road salt is used in the road section close to the lake. This development gives rise to concern about Lake Padderudvann. A possible conflict can arise between the need for passable and safe winter roads, with road salting as part of the road operation, and the desire to preserve water sources with regard to water quality, and animal and plant life. These previous investigations make Lake Padderudvann well suited for newer research into the long-term effects of road pollution. In 2001-2003 a new in-
vestigation was carried out by the University of Oslo and NIVA, financed by the Norwegian Public Roads Administration. This investigation focused on: • Consequences of road salt on the water circulation conditions of the lake. • Accumulation of pollutants in water layers, sediments, plants and animals. • Biological communities. Area description
The highway along the north side of Lake Padderudvann was constructed in 1969. The surrounding bedrock is rich in lime, which ensures high natural levels of calcium and pH in the lake. The lake is surrounded by forest areas and farms. The catchment area of the lake is 2.8 km2. The theoretical renewal of mixolimnion is about 15 months. The maximum
Figure 1. Lake Padderudvann 2001-2003 with the sampling stations. (Surface area 0,17 km2.)
depth of the lake is 21 meters. The outlet of Lake Padderudvann is located at the southwest end (fig. 1). Results
At some stations on the north side (the road side) of the lake, very high concen-
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
Figure 2. The vertical distribution of specific conductivity (mean ± standard deviation) in Lake Padderudvann during the period of 1947-1948, 1966-1967, 1980-1981, 19911992 and 2001-2003.
trations of calcium, sodium, and chloride were measured in 2001-2003. In addition to the natural geological contributions, wear and tear of the asphalt from studded tires contributes to the high calcium concentrations. The high sodium and chloride concentrations in the lake are caused by the road salt used in winter. The specific conductivity, which is the measure of the salt content, increased very slightly in Lake Padderudvann during the period between 1947-1948 and 1966-1967. From 1966-1967 to 2001-2003 the conductivity increased considerably (fig. 2). Since the last major investigation in 1991-1992 and up to 2001-2003, the increase in the conductivity was greater in the deepest water, due to the accumulation of salts, which are dominated by sodium and chloride ions. The water in Lake Padderudvann circulated to depths of 12-14 m during the period 2001-2003. Previously, in 1966-1967, the circulation varied more, namely between 13-18 m depths (fig. 3). 21
NORWEGIAN PUBLIC ROADS ADMINISTRATION (NPRA)
Figure 4. The periphyton community was rich in species/taxa, indicating high amounts of nutrients and ions, and the insignificance of toxic effects. Interesting findings included the identification of the red algae Chroodactylon ornatum and the green algae Chaetophora incrasata and as far as we know, neither of these species has been observed in any other fresh waters of Norway.
Figure 3. Scheme of circulation conditions in the meromictic Lake Padderudvann. There are large differencies in the physical, chemical and biological conditions in mixolimnion (aerobic) versus monimolimnion (anaerobic).
The most important factor causing this change in circulation depth is the accumulation of salts in deep water. Increasing differences in the salt concentration between the higher and lower levels of the water masses have reduced the variations in the circulation depth of the water in the lake. Due to the increased salt concentration in Lake Padderud, the salt content in the rest of the lake system, of which Lake Padderud is a part, is also affected. Measurements show that the accretion of salt from Lake Padderud has given three times higher salt content in the connected lakes. According to calculations of stability from previous research of Lake Padderudvann, full water circulation occurred for some years. Meteorologic conditions are important for the occurrence of full lake circulation. It is most likely that the water in Lake Padderudvann would have fully circulated just before freezing for the 1947 and 1965 investigations. It is highly likely that the chemical stability contributed to the fact that the water in the lake did not circulate fully in 1966. In 2001-2003, the stability had increased substantially due to a relatively large difference in the salt content between the upper water masses and the deep water. Sodium and chloride represent about 35 % of the chemical stability and contribute to the accumulation of salts in deep water. The chemical analysis of water and sediments showed a decrease in lead concentration compared to the 1992 study. The concentration of other metals (e.g. nickel and copper) had increased since 1992, probably due to increased traffic. The total PAH (polycyclic aromatic 22
Figure 5. The fish population was investigated using the standard test fishing gillnet series. Large population of perch (Perca fluviatilis), small population of pike (Esox lucicus), abundant population of roach (Rutilus rutilus) and some big individuals of tench (Tinca tinca) were caught in Lake Padderudvann.
hydrocarbons) concentrations in 2001 were significantly lower than in 1991. The large molecular PAH congeners were, however, at a similar or higher concentration level than observed before. Most chloroorganic compounds had low concentrations, but HCB (hexachlorobenzene) and OCS (octachlorostyrene) were found in high concentrations. The study of biological communities showed an increase in eutrophication between 1992 and 2002 (fig. 4). The populations of zooplankton and of fish seemed to be little affected by the highway pollution (fig 5).
run. This creates an unstable situation, as the shallow circulation depth depends on little wind during the later period of circulation. With more wind, the water masses under the circulation depth will mix with the water masses above. The consequence of a situation like this depends on how deep the lake water will finally circulate. Large amounts of matter (pollutants, nutrients etc.) that are accumulated in the deep water for a long period will be added to the circulating water. This will cause a serious pollution situation in Lake Padderudvann that will have negative consequences on the other lakes in the lake system.
Future development
If the lake continues to receive large amounts of road salt, the accumulation process in the deep water will continue. This trend may lead to an increased stability of the water in the lake. Increased salt concentrations in the deep water will reduce the circulation depth in the long
References Authors: T. Bækken, P.J. Færøvig. Series: NPRA Technology Division, Publication no. 106 (2004) Language: Norwegian with English summary
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
NORWEGIAN PUBLIC ROADS ADMINISTRATION (NPRA)
Foamed Glass – an Alternative Lightweight and Insulating Material Authors: Roald Aabøe, Norwegian Public Roads Administration, e-mail: roald.aaboe@vegvesen.no Even Øiseth, SINTEF, e-mail: even.oiseth@sintef.no
Granulated foamed glass (10 - 60 mm) produced by recirculating waste glass, is being investigated as a material for road construction purposes. With its insulating properties and light weight (350 – 400 kg/m3 design density), the material may both be used as a light weight filling material and frost protection layer/thermal insulation in roads or also for other civil engineering applications. Foamglass is produced using an environmentally friendly recycling technology for contaminated and toxic material. Ambitious environmental politics, international treaties and agreements, and a general change of attitude and awareness considering generating and handling waste has encouraged the development of national policies, codes, routines and contract clauses that motivate more extensive use of recycled materials. The Norwegian Public Roads Administration (NPRA) has initiated a programme in order to promote the use of recycled material in road structures. This includes incorporating secondary materials in the design guidelines and standards. Environmental issues and concerns need to be addressed during the entire life cycle from the design phase through maintenance to demolition. NPRA has a long tradition in applying various types of lightweight filling materials for road construction purposes such as, sawdust and bark residue, waste material from the production of cellular concrete blocks, Light Weight Clay Aggregate and blocks
of Expanded Polystyrene for a variety of applications also including blocks produced from recirculated EPS material. Production of foamglass
Presently a new option is being investigated involving the use of granulated foamed glass produced by recirculating waste glass. In Europe vast heaps of glass products are accumulating. At the same time as being a waste product it also constitutes a raw material for possible reuse. Foamglass is produced in a recycling technology for contaminated and toxic waste ranging from mercury lamps, industrial slag and flyash, PC- and TVtubes, and laminated glass to batteries. The process is based on the concept of
Figure 1: Typical foamglass particle
transforming finely ground glass powder from different glass sources mixed with an activator like silica carbide into glass foam. In the grinding process heavy metals are separated and recycled to metal melting plants. The powder is spread on a steel belt conveyor running through high temperature ovens whereby the powder expands, to leave the oven as a glass foam material. When the product leaves the oven it will crack and separate into smaller fragments due to the temperature shock. Monitoring programme
With its favourable drainage and insulating properties and light weight the material may both be used as a light weight filling material and/or frost insulating layer. Monitoring programmes have been initiated in order to investigate the long term performance of foamglass. Data relating to water content and densities measured in the field by the Public Roads Administration are shown in Table 1. The test sites will be monitored with more tests over time in order to observe changes in deformations, water content and density. Laboratory water absorption tests verifies these data. The material has been tested in a large cyclic loading triaxial apparatus
Table 1: – Field tests on foamglass material placed in road structures. Road project
Mat. type
Lodalen
Light
2001
2001
1500
Rv 120
Light
2001
2001
2900
500
15 - 65
E6 Mule
Light
2002
2002
550
295
25 - 35
E6 Eggemarka
Std.
2002
2003
1000
345
20
Postterminalen
Light
2000
2000
2750
E6 Rosendal
Std.
1999
2002
310
18
530
30
E6 Klemetsrud
Light
2003
2003
1100
0,5
271
5 – 20
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
Year
Field test
Volume Water m3 cont. % 3 -18
15 – 20
Density kg/m3
Fines < 8 mm (%)
325
30
23
NORWEGIAN PUBLIC ROADS ADMINISTRATION (NPRA)
The Norwegian Building Research Institute is preparing an European Technical Approval in 2005 for Hasopor based on a Common Understanding Assessment Procedure (CUAP).
PHOTO: NPRA
Road E6 Eggemarka
PHOTO: NPRA
Fig. 2: Road E6 Klemetsrud
Figure 3: Foamglass used as insulation material
to find the resistance to develop permanent deformation when exposed to repeated loading. For repeated loading applications the cyclic stress is recommended to be limited to 75 kPa. For use in road structures the material has elastic properties comparable to ordinary gravel commonly used as a roadbase material. Long term creep tests are preformed in a large oedometer with diameter 500 mm for loads up to 250 kPa. The creep deformation, defined as the deformation that will occur after day one, is modelled to be less than 1 % during the next 50 to 100 years for normal foundation loads. The material is suitable as thermal insulation and frost protection in both building and road application. The insulating properties have been tested in the laboratory. Dry, compacted material has a thermal conductivity as low as 0,10 W/mK at +10 ÂşC. The latest tests also include tests on wet and frozen material. 24
The results will, together with field experiences, be used to develop a design chart for use as a road insulation material. From a geotechnical point of view the design unit density is most critical in the competition with other light weight filling materials like LWA (550 kg/m3) and EPS (50/100 kg/m3). Tests conducted so far have led to implementation of Hasopor foamglass in the NPRA design manuals with a design unit density of 350 kg/m3 for the light type of Hasopor. Construction procedures and type of equipment for compaction haves been linked to various application of the material. After being placed in the fill and compacted, only small further deformations may be expected from the road pavement and live loads, in the short term about 12 % of the layer thickness. Observations over time (3 years) indicate that further crushing and deformations tend to be negligible. (<1 %).
Road E6 at Eggemarka, north of the town in Steinkjer includes an embankment, more than 15 m high constructed above a concrete tunnel, with the upper 6 m consisting of light weight filling materials. Both LWA (9000 m3) and foamglass (Hasopor 1000 m3) are used to reduce the weight on the culvert and to improve stability and reduce settlement problems. The fill worked as a diversion road that was in service for one year. Placing and compaction was carried out in 1 to 1.5 metre thick layers using crawler mounted dozers with track loads â&#x2030;¤ 40 kN/m2 performing some 3 passes over the area per layer. A volume reduction of 25 % was observed. Another 5 % reduction in volume was anticipated due to transport on site from local storage areas. No covering soils were placed on the foamglass slopes on the temporary fill. Density and water content measurements and sieving tests were conducted throughout the construction period both on loose material delivered on site, and on compacted material in the fill. Average figures from these tests are given in Table 1 page 23. Plate bearing tests and falling weight measurements (FWD) were also performed. So far there seems to be small differences between the rockfill and the light weight material. Settlements are monitored using settlement tubes, one tube on the top and one at the bottom of the lightweight filling layer for each material. Initial measurements were taken when the fills were completed and then again two months later. Conclusion
The monitoring programs together with the laboratory tests have shown that the material may be applied in road construction projects if the price is economically favourable compared to competitive products
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
TECHNICAL RESEARCH CENTRE OF FINLAND (VTT), BUILDING AND TRANSPORT
Implementation of Life Cycle Studies for Road Maintenance Projects So far, life cycle studies have been merely an interesting research subject, until VTT and Finnra (Finnish Road Administration) became inspired to implement them for the first time in the actual procurement of road maintenance. Two pilot projects proved that life cycle studies - even though limited could be applied today. However, more research is needed to create new design tools for life cycle performance. VTT and Finnra (Finnish Road Administration) have jointly developed a method for implementing life cycle studies in pavement procurement methods. This implementation was achieved through two in-situ pilot projects. This research study lasted for two years and it ended in January 2005. The objective of the research was to create preconditions for implementing the life cycle approach for pavement procurement. The other objective was to pinpoint the most important issues for life cycle analysis that need more research and development. The research was part of the Tekes's (National Technology Agency of Finland) Infra programme. VTT and Finnra together compiled the functional, technical and environmental requirements used in the invitations to tender in the pilot projects. The co-operation included the creation of requirements weightings, design methods and the judgement criteria in the evaluation of the tenders. Initially the 'Life cycle studies in the infra sector' project presented an idea about the implementation of life cycle studies in practical procurement. It was decided to perform this implementation in co-operation with Finnra, VTT and the parties involved in the field of pavement construction and maintenance. Co-operation was achieved using the Management Committee of the research project where
the consultants, contractors, and material suppliers were represented. Public discussions and information meetings were also arranged. The research was primarily carried out for Finnra but the results are open for all parties.
plan of action 10,5% construction plan 12%
constructor 7,5%
PILOT project Valkeakoski
Two pavement maintenance works were selected as pilot projects. The first one was the improvement of Road 307 between Valkeakoski and TykÜlä in 2003. The second pilot project was the improvement of Highway 9 between Turku and Lieto in 2004. Both pilots were so-called Design and Build projects, which included both the design and the construction work itself. The research started with defining the usual methods for comparing tenders and the contents of the orders for tenders in Design and Build procurement. One widely used method for comparing tenders is to use a weighting of 70 % for the tender price and a 30 % weighting for the quality components (Figure 1). In practice, the real weighting of the quality component has varied from 1% to 5%. Based on this information, new innovative comparison methods were developed, which also included life cycle studies. The life cycle studies were implemented through new tools, which were unfamiliar to the contractors and their designers. Thus, a short training course was arranged for the contractors and their consultants about the use of the tools. The tools used were the pavement design program APAS, the environmental impact calculation program Meli and the continuous settlement calculation program Tsarpix. The development of the new comparison methods and requirements tried to include all available life cycle components. It had to be possible to calculate or evaluate each component. Both pilot
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
cost 70%
Figure 1. The usual comparison of tenders in Design and Build projects.
projects had narrow financial constraints, which increasingly limited the selection of the components and comparison methods. The design life of the pavements in both pilot projects was chosen to be 20 years and the length of the guarantee period was five years. A modified version of the usual comparison method was applied in the first pilot project (Valkeakoski). The modified version focused on the environmental impact calculations, the service life-based pavement design and extra user delay costs. The quality and technical requirements of the pavement structure were amended to give a better description of the life cycle aspects. PILOT project Lieto
The objective of the second pilot project was to expand the life studies from the first pilot project. In order to simplify the comparison of the components, the price of the project was fixed. Therefore, the tenders were compared to each other based on the dimensions and quality of the pavements in question. The comparison method was developed to promote tenders, in which constructions were evaluated to present the best life cycle quality. 25
TECHNICAL RESEARCH CENTRE OF FINLAND (VTT), BUILDING AND TRANSPORT
The constructions were evaluated on the quality of the pavement, its lifetime and evenness. Due to the thick clay subgrade, the pavement has suffered from extensive settlement, longitudinal unevenness and flattening of the cross-section over the last forty years (Figure 2). The aim of the pavement rehabilitation was to correct the unevenness and to prevent this from recurring in the future. The new evenness evaluation method was developed to promote solutions having many small corrective actions instead of a few extensive ones. This meant that the changes in the vertical geometry of the pavement could play an important role. The tenders for the second pilot project were compared with a method that has been developed from a weighted multivariate analysis (Figure 3). The experiments with this comparison method were mainly positive. Yet, some contractors thought that omitting the price was a problem. The rate of the development process was experienced by some as too fast and by others too slow. A very positive attitude was found towards the continuous design methods like Tsarpix.
Deterioration models: new materials Evaluation of the environmental impacts Eco-indicators Deteriorationmodels: traditional and stabilized materials Service life-baseddesign
Level
Acquiring the site investigation data 2004
2005
2006
Extra user delay cost 5% Environmental impacts 10%
Quality of the pavement 40%
Other quality aspects 20% Fixed price!
Quality of the evenness 25%
Figure 3. The comparison of tenders in the second pilot project.
life cycle studies could also be applied today. These factors are extra user delay costs and the environmental impact of construction work. The research brought to light many factors that can limit life cycle studies and their reliability. The most important limiting factor is the quality and deficiencies of the site investigations. The life cycle-based procurement needs more input data and expertise from all partners involved in the construction and design than in the usual procurement process.
Figure 2. The unevenness of Highway 9 in Lieto. 26
2007
2008
Figure 4. The development timetable of life cycle components and their tools.
Conclusions
The research proved that some parts of
Development of the continuous measuring methods
According to the research the most urgent research issues are: - The development of service life-based design, including deterioration models - The development of an eco-indicator
system and its tools - The development of acquiring the site investigation data - The development of coherent evaluation methods Figure 4 presents an estimated timetable for the development of the life cycle components most urgently needed. The basic problem with life cycle studies is how to merge the different units of the components, like money, environmental impact and performance. The alteration can be made by converting all the components into prices or into points. The life cycle studies can and should be implemented in all phases of the construction process, not only when comparing tenders. There are advantages in the life cycle studies for society as a whole, with a better balance between investment costs and improved environmental quality.
Title: Pilot projects for life cycle studies in road maintenance Authors: Leena Korkiala-Tanttu, Jouko TÜrnqvist, Paula Eskola, Markku Pienimäki, Harri Spoof and Ulla-Maija Mroueh Publications series: Finnra Reports 13/2005 Language: Finnish with English abstract
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
Annotated reports from Technical Research Centre of Finland (VTT), Building and Transport
Development of an Operational Model for Maritime Incident Management Incident management has a significant influence on the functionality of the whole transportation system and the logistics chain. The objective is the prevention and quick handling of incidents as well as the reduction of damage caused by incidents. In addition to safety, incident management can improve the environmental and economic effects of incidents. Incident management covers precautions, advance planning, real-time incident management, post-analysis and incident reporting. The preliminary operational model for incident management of maritime traffic specified by this project comprises: • the aims of incident management. • the tasks of the authorities and other parties involved in incident management. • the vital solutions for developing incident management. With the help of this tool, incident management can be comprehensively developed in co-operation with the different parties involved in maritime operations. In addition to accidents and other serious incidents or situations which
could be dangerous to people and the environment, the operational model focuses on the management of frequent smaller incidents, especially those causing economic damage to transportation and the supply chain. Due to their frequency, they cause cumulative damage affecting many different parties and are significant in their combined effect. Accidents and other serious disturbances are rare and the operational model is based on a centralised administration and communication set-up. The main development solutions in the preliminary operational model are: • the setting-up of call centre operations for authorities in case of severe accidents. • the improvement of communication. • the creation of common operational models by setting up a co-operation forum including the key parties involved in maritime traffic. • the expansion of the role of vessel traffic management into a data management centre supporting incident management. • the development of the PortNet-
system to become a means of incident management communication. Other development procedures are: • the increase and expansion of collective training for the different parties involved. • improvements in identification and control of long-term incidents. • the consolidation and clarification of the tasks of the different authorities. The operational model needs to be further developed and implemented in different organisations.
Authors: Raine Hautala and Sanna Sonninen VTT, Juha Levo and Jukka Lähesmaa SysOpen Series: FITS reports 47/2004 Series: FITS reports 47/2004 Language: Finnish with English abstract The report is also available as a pdf file on http://www.vtt.fi/rte/projects/fits/ julkaisut/hanke4/fits47_2004.pdf
Park-and-Ride Information System The aim of the study was to define a parkand-ride information system for the new direct Lahti railway line (74 km) in Finland, both at the target stage of operation and at commencement, as well as the target groups of the information. In addition, the supply and demand of park-and-ride between Helsinki and Lahti in the Lahti motorway influence area was studied. The volume of park-and-ride alongside the new line was estimated as 800 cars daily in 2006 and 1,100 in 2025 which is equivalent to three to seven percent of the traffic volume of the Lahti motorway at Mäntsälä at the most. The first phase of the information system would include an Internet based information system, variable message signs on the road network, an incident information system on radio and fixed signs for the park-and-ride-system. Input data for the system will be gathered from the national joint public transport database,
Finnish Road Administration’s traffic and road weather monitor system, prospective Lahti motorway travel time prediction system, the prospective park-and-ride facility monitor system and from the internet portal for public transport services Matka.fi. The first phase should be in operation when the traffic commences. The marketing campaign of the parkand-ride system will be included into the marketing of the new rail service. The implementation and maintenance costs of the first phase of the park-andride information system i.e. the service to be implemented in 2006 was estimated as 730 000 Euro and after that at approximately 145 000 Euro annually. The estimated benefits of the system would be about 240 000 Euro per year. The implementation of the park-and-ride system together with its information system decreases traffic volumes and congestion. It also improves traffic flow at incidents
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
and increases the number of train passengers by about 650-700 daily of which about 150 are due to the real time information. The system also improves the image of transport services, decreases traffic emissions, and decreases the need for the construction of new parking facilities in the centres of Helsinki and Tikkurila. Title: Preliminary study of the park-and-ride information system for Lahti direct railway line Authors: Marja Rosenberg, Mikko Lehtonen and Jukka Räsänen Series: Publications of the Ministry of Transport and Communications 62/2004 Language: Finnish The report is also available as a pdf file on http://www.mintc.fi/ oliver/upl116Julkaisuja%2062_2004.pdf
27
Annotated reports from Institute of Transport Economics (TØI)
Evaluation of NDF Co-financed Transport Projects The evaluation concerns Nordic Development Fund (NDF) transport sector interventions 1989-2002 and covers 24 interventions in 16 countries in Africa, Asia and Latin America. Total NDF funding amounted to Euro 152 million (2002 exchange rates) of which roads sector interventions received 85 per cent. The main conclusion is that transport sector interventions have performed satisfactorily and that the sector should remain an important part of the NDF development assistance portfolio. The road sector is recommended to remain the focal point of NDF’s transport sector operations. Gradually, capital investment projects will be replaced by a demand for softer type activities, among which institutional reform and capacity building should be given priority.
Title: Evaluation of NDF Co-financed Transport Projects and NDF’s Engagement in the Transport Sector in General Authors: Bent Larsen, Henning Lauridsen Report no: 723/2004 Language: English, http://www.toi.no/program/ program.asp?id=1051624
The road sector is recommended to remain the focal point of NDF’s transport sector operations.
Impact of Main Road Investments The Bergen and Oslo toll rings were established in 1986 and 1990 to speed up road investments. In Bergen, the congestion problems have more or less been solved, while congestion remains unaltered in Oslo. Urban growth has contributed to a strong increase in traffic in both cities. Oslo has experienced a relatively positive public transport development, since 20 per cent of the investments have been allocated to public transport while subsidy levels have been fairly stable. In Bergen, where all investments have been reserved for road traffic and subsidy levels have decreased, there is also a strong decrease in public transport demand.
Title: Impact of main road investments in Bergen and Oslo Authors: Jon Inge Lian Report no: 770/2005 Language: Norwegian with summary in English. http://www.toi.no/program/ program.asp?id=1051648
In Bergen, the congestion problems have more or less been solved by new roads.
Stated Preference Surveys on Internet Institute of Transport Economics (TØI) has carried out analyses of whether the data collection methods used affects the results. This report summarise the experiences so far of using Stated Preference surveys on the Internet to find passengers preferences. The analyses identify whether those who choose to use the Internet have
28
preferences which are different to those who choose paper-based or home-based interviews, or whether it is the form of the interview which affects the results. In addition, the report present key characteristics of those who choose the Internet and those who choose paper-based/ home-based interviews.
Title: Stated Preference Surveys on Internet - an Effective Method for Finding Passengers' Preferences? Summary report Authors: Åse Nossum, Inge Brechan, Nils Fearnley Series: TØI Report 763/2005 Language: Swedish and English, http://www.toi.no/program/ program.asp?id=1025445
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
Annotated reports from Institute of Transport Economics (TØI)
Mobility and ICT in Norway Daily life in Norway for families with children consists of activities that are spread geographically. People work in one place and live in another while activities that were earlier tied to the home are done other places. The development of “new” family structures while at the same time there is the distribution of daily activities has opened the way for new and more flexible forms for informa-
tion and communication technology (ICT) to coordinate the interaction between family members. The need for flexible transport to link together activities is also an issue. In this project the interaction between ICT, physical mobility and social life among different types of families is examined. We ask how families use ICT to coordinate everyday life and how ICT and physical mobility interact.
Title: Mobility in everyday life. A qualitative study of the use of car and ICT in families with children Authors: Randi Hjorthol, Mona Hovland Jakobsen, Rich Ling, Susanne Nordbakke, Leslie Haddon Report no: 754/2005 Language: Norwegian with summary in English. http://www.toi.no/program/ program.asp?id=947856
Young People and Transport Mode Choice To influence young people’s choice of more environmental friendly transport it is necessary to visualize the independence that public transport represents. This is the conclusion in a report issued by Institute of Transport Economics (TØI). The report is a review of 14 Nordic studies of conditions influencing young people’s transport mode choice. Structural and cultural explanations are used. Transport mode choice is related to
transport resources and to people’s attitude to transport modes. Above all, the choice is pragmatic, related to use of time and required mobility. To influence young people’s choice of more environmental friendly transport it is necessary to visualize the independence that public transport represents. The review indicates the need of utilization of existing data as well as new studies.
Title: Young people and transport mode choice. A summary of Nordic surveys Authors: Susanne Nordbakke, Alberte Ruud Report no: 760/2005 Language: Norwegian with summary in English. http://www.toi.no/program/ program.asp?id=993103
Logistics of Beverage Packaging A replacement of refillable beverage packaging by Non Refillable PolyEthylene Terephthalate (NR PET) beverage packaging will reduce logistical costs and give rise to environmental gains in reverse logistics. This is one of the results from the study that focuses on reverse logistics from different regions and for different kinds of beverage packaging in Norway.
The logistical costs and environmental effects are studied in the chain of logistical activities involving grocery trade, grocery producers and the recycling industry. Calculations show that in a scenario where all refillable beverage packaging are replaced by NR PET, the logistical costs are more than halved. Also, CO2 emissions are reduced by 43%.
Title: Costs and CO2 emissions in reverse logistics of beverage packaging Author:Olav Eidhammer Series: TØI Report no: 771/2005 Language: Norwegian
A Guide to Improved Safety in Public Transport The object of the guide is to enhance how public transport companies work in order to improve safety in their own company. The guide deals with measures directed towards employees in land based public transport (coach, rail and taxi). The measures will help prevent violence, robbery and threats in public transport, as well as minimize the extent of damage caused by
such actions. The guide describes measures that the employer may implement on different levels, and gives examples of companies that run excellent safetyimproving programmes. The guide also contains a chapter describing the legal framework for safety enhancement, an index, recommended litterature, contacts and useful web sites.
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Title: Improved safety in public transport. A guide with examples of programmes of action Authors: Trine Hagen Report no: 769/2005 Language: Norwegian
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Annotated reports from VTI
Traffic Safety Measures and Their Observance. Compliance with Speed Limits, Seat Belt Use and Driver Sobriety On behalf of the Swedish Institute for Transport and Communications Analysis (SIKA), an estimate has been made of the effect on traffic safety of total compliance with the current speed limits, seat belt use and driver sobriety. Observance varies among the three measures. Observance of speed limits is low, while observance of driver sobriety is high. T the same time, while speeding causes only a moderate deterioration in traffic safety, being intoxicated while driving involves a dramatic rise in risk. On the whole, the greatest traffic safety problem is violation of the speed limits, and these results in 150–200 fatalities annually. Owing to inadequate observance of the other two measures, 50–100 per-
sons are killed annually. The report does not deal with the matter of how observance should be increased. There are, however, interlock systems available for increasing observance, as alternatives/complements to greater surveillance and/or higher fines. Compared with the death risk of the “exemplary” driver group, lack of observance more than doubles the death risk. A very high degree of observance of the three measures would mean that the number killed in traffic would be reduced by almost 50 per cent. What is of interest is that observance is not randomly distributed among the three measures. Both the drivers who adjust their driving to the three measures, and those who simultane-
ously contravene two or three of the measures, are overrepresented in traffic. It is at the same time important that speed reduction reinforces the other two traffic safety measures. Estimation of the effect of alcohol is very uncertain, since the permitted alcohol levels vary between countries. Title:Traffic safety measures and observance. Compliance with speed limits, seat belt use and driver sobriety Authors: Göran Nilsson Series: VTI meddelande 951A Language: English The report is also available as a pdf file on www.vti.se/publications
The Influence of Road Surface Condition on Driving Comfort The decision support system for the maintenance of paved roads, PMS, of the Swedish Road Administration (SRA) comprises a number of models for estimating the costs of road management authorities, road users and society at large. In 1998 VTI was commissioned by the SRA to carry out a comprehensive project with the objective of revising and augmenting these traffic effect models. The project is entitled “Traffic effects of the road surface” and has comprised a number of subprojects. The primary aim of this study has been to investigate, in a field study, the relationship between the roughness of the road surface (expressed in terms of the International Roughness Index, IRI, with the units mm/m) and the perceived driving comfort of motorists, as well as their willingness to pay for improved driving comfort. 50 test subjects were asked to drive a car over nine 500 m long sections with different surface standards. The mean of the measured IRI on these road sections varies from 0.8 mm/m on the smoothest section to 10.5 mm/m on the roughest. In conjunction with the investigation, the test subjects were interviewed by a 30
test leader. During the interview, they were asked which factors are significant for driving comfort and how they perceived driving comfort on the different sections. The state/condition of the asphalt surfacing was considered to have the greatest significance, followed by the car and the behaviour of other road users. Density of traffic was considered to have the least significance. The test subjects were also asked to say what significance different defects in the surfacing had on driving comfort. What is most important for a comfortable car journey is that there are no holes/depressions in the surfacing. This is followed by ruts, roughness that causes vibrations, and bumps and subsidence. The test subjects were asked to make a general assessment of driving comfort on a five-degree scale during their drive over the nine sections. A clear relationship was found between the assessment that the test subjects made and the measured IRI, i. e. the higher the IRI, the worse driving comfort was judged to be. The physical impact caused by the different surface standards of the test sections was also investigated by placing a dummy equipped with triaxial accelero-
meters in the passenger seat of the car that drove over the test sections. The willingness of the test subjects to pay for improved comfort associated with the condition of the road surface was also investigated by three methods: Stated Preference (Choice) and Contingent Valuation Method (driving comfort versus petrol price and trip time). A relatively high willingness to pay was obtained, but the methods gave very different results. It has therefore been impossible to posit a comfort cost model on the basis of these. This requires further studies and development of the methods.
Title: The influence of road surface condition on driving comfort Authors: Stefan Grudemo, Anita Ihs, Mats Wiklund Series: VTI meddelande 957 Language: Swedish with English summary The report is also available as a pdf file on www.vti.se/publications
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Annotated reports from VTI
The Friction on Wet, Smooth Ice for New and Used Winter Tyres It has been argued that the grip of winter tyres on ice and snow deteriorates with age to such an extent that winter tyres above a certain age, e. g. 10 years should be forbidden to use. Little research data do however exist. This investigation has been carried out by VTI in order to get a better background for legal decisions. The results would also be of use for ordinary consumers as guidance. This investigation that was carried out on wet, smooth ice is the third of three part studies. The first was on smooth ice at -3C and the second on rough ice at -3C. They have been reported in VTI meddelande 923 and VTI notat 34-2003. The aim of this investigation is to study the correlation between ice grip of winter tyres and their age, tread depth and tread rubber hardness and for studded tyres also stud protrusion and stud force. The investigation comprises 23 studded and 42 non-studded winter tyres and four
summer tyres mainly of the in Sweden popular brands Gislaved, Michelin and Good Year, primarily of size 195/65-R15. Most of the tyres had been driven in ordinary traffic. They were manufactured from 1981 to 2003. A small number of new winter tyres were also tested. As reference some new summer tyres were tested as well. The steering and braking performance of the tyres has been measured in a special climate controlled indoor high speed flat bed test facility developed by VTI. Very good correlation has earlier been found between results from the facility and lap time results from ice track circuit tests with cars as well as pure braking and cornering tests with cars on ice tracks. No age related deterioration of the ice grip was found for the fully studded winter tyres with stud protrusion 1 mm and higher. The ice grip deteriorated with increasing age for non-studded winter
tyres and studded tyres with stud protrusion less than 0,9 mm. The results also show that on wet, smooth ice studded tyres with stud protrusion 1 mm and higher are much superior to non-studded tyres including the specialised studless winter tyres often called “friction tyres”. The difference in friction within the groups are however quite large. Title:The friction on wet smooth ice for new and used winter tyres. An investigation concerning the influence of age, tread depth, tread rubber hardness, stud protrusion and stud force. Authors: Olle Nordström Series: VTI meddelande 965 Language: Swedish with English summary The report is also available as a pdf file on www.vti.se/publications
Swedish Road Account – Mälardalen 1998–2002 In 1996 the Swedish Road Administration began systematically to collect and record costs associated with new construction, improvement, maintenance and operation of the national road network in a system known as VERA (an acronym for Verksamhetsuppföljning och resultatanalys – or in English, “activity follow-up and results analysis”). Information about traffic and the composition of the infrastructure in terms of road categories and maintenance classes can be obtained from the SRA Road Data Band (VDB). VDB’s frame of reference is a system of nodes and links that represent the national
road network. Conversely, VERA’s frame of reference consists of executed objects that can be linked to a geographical site, mainly via a road number and a date identifying the affected municipality. The purpose of this study has been to create a register of costs, infrastructures, and associated traffic that ties the VERA cost data to the VDB infrastructure and traffic data at the most detailed level possible. It was found that, within the context of national road maintenance, operating areas are currently the smallest well-defined units that can be created. The register is a pilot study and restricted to the
operating areas in the area of Mälardalen. This VTI report provides information about data gathering and the recorded data. The purpose of this account is to provide future users of the register with a means of quickly forming an accurate idea of its contents. Title:Swedish Road Account Mälardalen 1998-2002 Authors: Fridtjof Thomas Series: VTI rapport 500A Language: English The report is also available as a pdf file on www.vti.se/publications
Optimal Taxation of Intermediate Goods in the Presence of Externalities: a Survey towards the Transport Sector The literature on optimal taxation with emphasis on intermediate goods, or more specific, on freight (road) transport is surveyed in a VTI study. There are two models frequently used. Firstly, the one emanated from a paper of Diamond & Mirrlees where the production efficiency lemma made it clear that intermediate goods were not to be taxed. Secondly, the Ramsey-Boiteux model where a cost-ofservice regulation imposes a budget
constraint for the regulated firm. In the latter model, in contrast to the first, freight transports (intermediate goods) are to be taxed in the Ramsey tradition, and thus trades the production efficiency lemma against a budget restriction. Welfare effects due to environmental tax reforms, with emphasis to what has become to be known as the double dividend hypothesis, are discussed as well. Finally, administrative costs in the
NORDIC ROAD & TRANSPORT RESEACH NO. 1 2005
context of optimal taxation are touched upon, a subject that is to a large degree repressed in optimal tax theory. Title: Optimal Taxation of Intermediate Goods in the Presence of Externalities Authors: Joakim Ahlberg Series: VTI meddelande 970A Language: English The report is also available as a pdf file on www.vti.se/publications 31
Questions concerning the content of the articles, or orders for the publications referred to, should be directed to the publishing institution, see addresses below. REQUEST FOR BACK ISSUES, AND NOTIFICATION OF ADDRESS CHANGES. Readers outside the Nordic countries: see Swedish address. Readers in the Nordic countries: see addresses below. Web site: www.vti.se/nordic
Denmark Helen Hasz-Singh Guldalderen 12 Postboks 235 Fløng 2640 Hedehusene Phone: +45 46 30 70 00 Direct: +45 46 30 7116 Fax: +45 46 30 71 05 Web site: www.vejdirektoratet.dk
Norway Harald Aas Institute of Transport Economics (TØI) P.O. Box 6110 Etterstad N-0602 Oslo Phone: +47 22 57 38 00 Fax: +47 22 57 02 90 E-mail: harald.aas@toi.no Web site: www.toi.no
Finland Kari Mäkelä VTT Building and Transport P.O. Box 1800 FIN-02044 VTT Phone: +358 20 722 45 86 Fax: +358 20 722 70 56 E-mail: kari.makela@vtt.fi Web site: www.vtt.fi/rte/indexe.html
Norway Thorbjørn Chr. Risan Norwegian Public Roads Administration P.O. Box 8142 Dep N-0033 Oslo Phone: +47 73 95 46 48 Fax: +47 73 95 46 31 E-mail: thorbjorn.risan@vegvesen.no Web site: www.vegvesen.no
Iceland Hreinn Haraldsson Public Road Administration Borgartún 7 IS-105 Reykjavik Phone: +354 563 1400 Fax: +354 562 2332 E-mail: hrh@vegag.is Web site: www.vegagerdin.is
Sweden Michael Höglund VTI SE-581 95 Linköping Phone: +46 13 20 42 17 Fax: +46 13 14 14 36 E-mail: michael.hoglund@vti.se Web site: www.vti.se