Dec 2010 CTR Library Research Digest

Research Digest FORWARD ALL REQUESTS TO: The University of Texas at Austin Center for Transportation Research LIBRARY 1616 Guadalupe St. | Suite 4.202 | Austin, Texas 78701 Phones: (512) 232-3126 and (512) 232-3138 Email: ctrlib@austin.utexas.edu In this Issue:

Southwest Region University Transportation Center (SWUTC) Reports

Table of Contents Item 1.

Compendium of Student Papers : 2009 Undergraduate Transportation Scholars Program

(SWUTC/09/ 476660-00003-2).............................................................................................................................

1

Item 2.

On Jointly Analyzing the Physical Activity Participation Levels of Individuals in a Family Unit Using a Multivariate Copula Framework (SWUTC/10/ 161020-1)...................................................

1

Item 3.

Network methods for project selection based on optimizing environmental impact (SWUTC/10/ 161026-1)...............................................................................................................................................................

2

Item 4.

Climate Change/Variability Science and Adaptive Strategies for State and Regional Transportation Decision Making (SWUTC/10/ 167165-1)............................................................................

2

Item 5.

Quantifying Travel Time Variability in Transportation Networks (SWUTC/10/ 167275-1)..................

3

Item 6.

Valuing Real Estate Externality-Based Options in Development of Transit System Projects

(SWUTC/10/ 169112-1)........................................................................................................................................

3

Item 7.

Ant Colony Optimization Algorithm for Signal Coordination of Oversaturated Traffic Networks (SWUTC/10/ 169113-1)....................................................................................................................

4

Item 8.

Measuring the Benefits of Intercity Passenger Rail : A Study of the Heartland Flyer Corridor

(SWUTC/10/ 169116-1)........................................................................................................................................

4

Item 9.

Examining the Influence of Tolls on Commute Departure and Route Choice Behavior in the Chicago Region (SWUTC/10/ 169200-1)............................................................................................................

5

Item 10.

Robust Pricing of Transportation Networks Under Uncertainty (SWUTC/10/ 169206-1)......................

5

Item 11.

State Commercial Vehicle Security Enforcement : Operations, Technologies, and Barriers

(SWUTC/10/ 473700-00074-1).............................................................................................................................

6

Item 12.

Physically Based Model for Predicting the Susceptibility of Asphalt Pavements to MoistureInduced Damage (SWUTC/10/ 476660-00012-1).............................................................................................

6

Item 13.

Increasing Awareness Among Students about Careers in Transportation (SWUTC/10/ 476660-

00045-1)...............................................................................................................................................................

7

Item 14.

A Road Pricing Methodology for Infrastructure Cost Recovery (SWUTC/10/ 476660-00064-1)..........

7

Item 15.

A Comprehensive Examination of Heavy Vehicle Emissions Factors (SWUTC/10/ 476660-

Item 16.

Item 17.

00067-4)...............................................................................................................................................................

Predicting the Incremental Effects on Transit Ridership Due to Bus-On-Shoulder Operations

(SWUTC/10/ 476660-00073-1)............................................................................................................................

Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation

(SWUTC/10/ 476660-00074-1)................................................................................................................................

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Research and Technology Implementation Office

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Research Digest Item 1 Compendium of Student Papers : 2009 Undergraduate Transportation Scholars Program SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/09/ 476660-00003-2 • 2009

This report is a compilation of research papers written by students participating in the 2009 Undergraduate Transportation Scholars Program. The ten-week summer program, now in its nineteenth year, provides undergraduate students in Civil Engineering the opportunity to learn about transportation engineering through participating in sponsored transportation research projects. The program design allows students to interact directly with a Texas A&M University faculty member or Texas Transportation Institute researcher in developing a research proposal, conducting valid research, and documenting the research results through oral presentations and research papers.

The papers in this compendium report on the following topics, respectively: 1) appropriate time-to-clear values for use in developing left-turn lane warrants; 2) driver behavior at freeway interchanges with horizontal signing; 3) quality assurance in speed data collection methods at high speeds; and 4) measuring traveler’s willingness-to-pay for time savings.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/compendiums/476660-00003-2.pdf

Item 2 On Jointly Analyzing the Physical Activity Participation Levels of Individuals in a Family Unit Using a Multivariate Copula Framework SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 161020-1 • 2010

The report focuses on analyzing and modeling the physical activity participation levels (in terms of the number of daily “bouts” or “episodes” of physical activity during a weekend day) of all members of a family jointly. Essentially, we consider a family as a “cluster” of individuals whose physical activity propensities may be affected by common household attributes (such as household income and household structure) as well as unobserved family-related factors (such as family life-style and health consciousness, and residential location-related factors). The proposed copulabased clustered ordered-response model structure allows the testing of various dependency forms among the physical activity propensities of individuals of the same household (generated due to the unobserved family-related factors), including non-linear and asymmetric dependency forms. The proposed model system is applied to study physical activity participation of individuals, using data drawn from the 2000 San Francisco Bay Area Household Travel Survey (BATS). A number of individual factors, physical environment factors, and social environment factors are considered in the empirical analysis. The results indicate that reduced vehicle ownership and increased bicycle ownership are important positive determinants of weekend physical activity participation levels, though these results should be tempered by the possibility that individuals who are predisposed to physical activity may choose to own fewer motorized vehicles and more bicycles in the first place. Our results also suggest that policy interventions aimed at increasing children’s physical activity levels could potentially benefit from targeting entire family units rather than targeting only children. Finally, the results indicate strong and asymmetric dependence among the unobserved physical activity determinants of family members. In particular, the results show that unobserved factors (such as residence location-related constraints and family lifestyle preferences) result in individuals in a family having uniformly low physical activity, but there is less clustering of this kind at the high end of the physical activity propensity spectrum.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/161020-1.pdf _______________________________________________________________________________________________

Research and Technology Implementation Office

December 2010

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Research Digest Item 3 Network methods for project selection based on optimizing environmental impact SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 161026-1 • 2010

Traditionally, transportation road networks have been designed for minimal congestion. Unfortunately, such approaches do not guarantee minimal vehicle emissions. Given the negative impacts of vehicle pollutants as well as tighter national air quality standards, it is critical for regions to be able to identify capacity modifications to road networks such that vehicle emissions are minimal. This ability combined with land use changes and opportunities for non-auto travel are paramount in helping regions improve air quality. However, network design research has yet to directly address this topic.

To fill this apparent gap in network design research, an emissions network design problem and solution method are proposed in this report. Three air pollutants are considered: hydrocarbons, nitrogen oxides, and carbon monoxide.

The proposed model is applied to two road networks: Sioux Falls, ND and Anaheim, CA. The model is a bi-level optimization problem solved using a genetic algorithm and incorporates the influence of demand uncertainty.

Findings indicate designing for minimal congestion tends to increase emissions of criteria air pollutants. However, not adding capacity to a road network also increases emissions of pollutants. Therefore, an optimization problem and solution method, such as the model presented here, is useful for identifying capacity additions that reduce vehicle emissions. It is also useful for understanding the tradeoffs between designing a network for minimal congestion versus minimal vehicle emissions.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/161026-1Abstract.htm

Item 4 Climate Change/Variability Science and Adaptive Strategies for State and Regional Transportation Decision Making SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/10/ 167165-1 • 2010

The objective of this study was to generate a baseline understanding of current policy responses to climate change/variability at the state and regional transportation-planning and -decision levels. Specifically, researchers were interested in the question of whether state and regional governments were currently including climate change impacts or vulnerability issues in their decision and planning processes. The focus of this report is on the basic question: are state DOTs and MPOs in the United States addressing the issue of climate change in general and, more specifically, the issue of adaptation to potential climate change and -variability impacts? The research approach included content analysis, an in-depth survey of stakeholders, and interviews with stakeholders. The aggregate findings reveal that acceptance and movement in state DOTs and MPOs on these complex climate-related issues and solutions, where they exist at all, are slow. Mitigating the impacts from transportation appears to still be the primary policy linkage between climate change and transportation for these agencies. Public interest, political acceptance, and lack of downscaled state- and regional-level data are all factors that require further attention in the climate change/transportation nexus.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/167165-1.pdf

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Research and Technology Implementation Office

December 2010

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Research Digest Item 5 Quantifying Travel Time Variability in Transportation Networks SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 167275-1 • 2010

Nonrecurring congestion creates significant delay on freeways in urban areas, lending importance to the study of facility reliability. In locations where traffic detectors record and archive data, approximate probability distributions for travel speed or other quantities of interest can be determined from historical data; however, the coverage of detectors is not always complete, and many regions have not deployed such infrastructure. This report describes procedures for estimating such distributions in the absence of this data, considering both supply-side factors (reductions in capacity due to events such as incidents or poor weather) and demand-side factors (such as daily variation in travel activity). Two demonstrations are provided: using data from the Dallas metropolitan area, probability distributions fitting observed speed data are identified, and regression models developed for estimating their parameters. Using data from the Seattle metropolitan area, the appropriate capacity reduction applied to planning delay functions in the case of an incident is identified.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/167275-1.pdf

Item 6 Valuing Real Estate Externality-Based Options in Development of Transit System Projects SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/10/ 169112-1 • 2010

Capital-intensive transit projects rely on strong public support and availability of funds. While the general public has become a strong advocate for transit systems, budget shortfalls and financial constraints are still resulting in delays in project delivery. In such business environment, the public sector has an opportunity to partner with the private sector to deliver and operate needed infrastructures. In public-private arrangements, the private sector typically is unwilling to accept the system ridership risk, making such projects financially unfeasible. However, transit projects undoubtedly create value that is not internalized by the developer. The completion of a transit system not only increases the values of properties in the affected area, but also brings incremental tax revenue to the public sector. Thus, some of this newly created value can be shared with the private sector to make the project financially feasible. The objective of this paper is to develop a method for designing externality-based option and a model for its valuation. The proposed valuation model is based on the concept of auctions, where the price-jump results from the introduction of the new transit system. The numerical example results show that externality-based option could reduce private sector risk and add value to the private developer, making transit project more attractive.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/169112-1.pdf

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Research and Technology Implementation Office

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Research Digest Item 7 Ant Colony Optimization Algorithm for Signal Coordination of Oversaturated Traffic Networks SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/10/ 169113-1 • 2010

Traffic congestion is a daily and growing problem of the modern era in mostly all major cities in the world.

Increasing traffic demand strains the existing transportation system, leading to oversaturated network conditions, especially at peak hours. Oversaturation occurs when queues of vehicles fill the streets approaching intersections and interfere with the performance of adjacent upstream intersections. Traffic conditions, measured based on the overall throughput of vehicles and total travel time, can be improved by an effective employment of intelligent transportation system techniques. While a significant amount of research has been devoted to the development of signal control algorithms under normal traffic conditions, a relatively small number of studies have explicitly considered oversaturated conditions. The overall objective of this study was to investigate the effectiveness of the Ant Colony Optimization (ACO) algorithm in solving the traffic signal control problem under oversaturated conditions. Due to its ability to reach optimality conditions and identify acceptable solutions efficiently, ACO was a good candidate for a practical use. This research compared the performance of ACO to that of another heuristic method, the genetic algorithm (GA). The methods were applied to identify signal control strategies for two example networks. The results demonstrate that ACO was able to identify fit solutions more reliably than the GA-based approach.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/169113-1.pdf

Item 8 Measuring the Benefits of Intercity Passenger Rail : A Study of the Heartland Flyer Corridor SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/10/ 169116-1 • 2010

In recent years, the policy and regulatory environment for intercity passenger rail in the United States has shifted dramatically, sparking a renewed interest in intercity passenger rail among policy makers, planners, and the general public. As the nation expands its passenger rail network, a better understanding of the mobility provided by short- to medium-distance corridors is desired. This study examined the Heartland Flyer, a 206-mile intercity passenger rail route between Oklahoma City, Oklahoma, and Fort Worth, Texas. Researchers analyzed responses to an on-board survey, distributed to passengers in April and July of 2009, to identify who was using the service and how the service impacted regional mobility.

The key measure used to identify the mobility impacts was the passengers’ self-reported alternatives for travel if the Heartland Flyer were discontinued. This study also identifies the economic impact of the rail service, measured through total spending on certain items (and the associated sales tax revenue). The findings of this study can be used in a variety of potential applications for all levels of passenger rail planning, including statewide rail planning, corridor-specific studies, and station-area planning, both in the southwestern United States and in other regions.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/169116-1.pdf

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Research and Technology Implementation Office

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Research Digest Item 9 Examining the Influence of Tolls on Commute Departure and Route Choice Behavior in the Chicago Region SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 169200-1 • 2010

In the United States, a significant number of individuals depend on the auto mode of transportation. The high auto dependency, in turn, has resulted in high auto travel demand on highways. The resulting traffic congestion levels, surging oil prices, the limited ability to address increased auto travel demand through building additional transportation infrastructure, and the emphasis on reducing GHG emissions has led to the serious consideration and implementation of travel demand management (TDM) strategies in the past decade. Congestion pricing is a frequently considered TDM option to alleviate travel congestion in urban metropolitan regions. Congestion pricing might induce changes in activity location, travel route, departure time of day, and travel mode. The current study contributes toward understanding the influence of congestion pricing on commuter behavior by specifically examining what dimensions of commuter travel behavior are affected as a response to congestion pricing. Specifically, we formulate and estimate a joint disaggregate model of commute departure time and route choice drawing from the 2008 Chicago Regional Household Travel Inventory (CRHTI). The empirical analysis demonstrates the significance of individual and household socio-demographics on commuter behavior. The results also highlight how vehicle availability plays an important role in determining individual’s sensitivity to travel time and travel cost. To demonstrate the applicability of the joint modeling framework to determine optimal toll fares, we compute value of travel time measures for different demographic groups.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/169200-1.pdf

Item 10 Robust Pricing of Transportation Networks Under Uncertainty SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 169206-1 • 2010

Both public and private entities are concerned with the impacts of future toll revenue, and the effects of tolled facilities on system congestion. Due to the inherent complexity of transportation systems, it is impossible to predict travel demand and congestion conditions exactly, and simplistic attempts to account for this consistently underestimate true levels of congestion. Thus, in the context of roadway pricing, there is a need to develop mathematical models which explicitly account for both demand and supply uncertainty in both the short-term and long-term time scales.

This project will develop these models, which will be suitable either to determine the best pricing policies to maximize revenue or minimize congestion, or to evaluate alternative toll policies according to these metrics. Thus, these models will produce more accurate predictions of toll revenues and congestion levels than are available using current methods.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/169206-1.pdf

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Research and Technology Implementation Office

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Research Digest Item 11 State Commercial Vehicle Security Enforcement : Operations, Technologies, and Barriers SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 473700-00074-1 • 2010

This report details the results of a survey of state enforcement agencies concerning past, present, and future enforcement practices and advanced technology use for commercial vehicle security, as well as recommendations for future improvements. The study examines practices in 19 states, including 7 land border crossing states and 11 states with one or more major marine ports of entry. Current technology applications, future needs, and past and existing barriers to implementation are all identified. The study also examines both successes and needs for cooperation between federal, state, and industry stakeholders. Particular focus is also placed on identifying changes that have occurred since 9/11.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/473700-00074-1.pdf

Item 12 Physically Based Model for Predicting the Susceptibility of Asphalt Pavements to Moisture-Induced Damage SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

SWUTC/10/ 476660-00012-1 • 2010

This study presents a novel moisture-induced continuum damage model for asphalt concrete. Moisture-induced damage is treated realistically as two mechanisms: (1) degradation of the adhesive bond between the asphalt mastic and aggregates and (2) degradation of the cohesive strength of the mastic. The moisture-induced damage model is formulated in a novel way, accounting for the gradual, irreversible degradation of a mix using continuum damage mechanics. Different mechanistic evolution laws are proposed for predicting adhesive and cohesive moisture-induced damage. To the authors’ best knowledge, this model is the first continuum model to capture all facets of realistic asphalt mix response. Moreover, a time- and rate-dependent damage constitutive law is proposed to predict crack nucleation and propagation due to different mechanical loading conditions. The moisture-induced and mechanicallyinduced damage models are integrated into a three-dimensional nonlinear viscoelastic-viscoplastic constitutive model to allow for more realistic prediction of damage evolution in asphalt concrete under various traffic and environmental loading conditions. Numerical integration algorithms are presented for implementing the model in the well-known finite element code Abaqus. Finally, various aspects of the integrated continuum damage mechanics model are investigated and found to match the qualitative behavior of experiments. The current moisture-induced damage model can be used by pavement engineers to predict the time frame over which moisture-induced damage may occur and to rank asphalt mixtures for moisture damage susceptibility.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00012-1.pdf

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Research and Technology Implementation Office

December 2010

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Research Digest Item 13 Increasing Awareness Among Students about Careers in Transportation SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / TEXAS SOUTHERN UNIVERSITY (TSU). CENTER FOR TRANSPORTATION TRAINING AND RESEARCH

SWUTC/10/ 476660-00045-1 • 2010

This paper focuses on determining the best way to improve the study habits and academic management skills of summer transportation students in grades 9 through 11. To find the most useful teaching method, 12 students were exposed to three learning methods. Students were taught via field trips, hands-on activities, and lectures. This work describes the program and teaching methods applied. Further research is required to fully determine which method would be most appropriate for students considering careers in the transportation industry.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00045-1.pdf

Item 14 A Road Pricing Methodology for Infrastructure Cost Recovery SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 476660-00064-1 • 2010

The purpose of this research is to provide a theoretical framework for future commercial vehicle user-charging using real-time vehicle weight and configuration information collected using weigh-in-motion (WIM) systems. This work provides an extensive review of both mechanisms and technologies employed for commercial and passenger vehicle user-charging worldwide. Existing commercial vehicle-user charging structures use only broad vehicle classifications to distinguish between vehicles for the pricing of user-fees. The methodology proposed in this study employs highway cost allocation methods for development of an “Axle-Load” toll structure. A theoretical case study, based on information from Texas State Highway 130, is performed to explore the equity improvements that could be achieved through implementation of this proposed structure. Some sensitivity analysis is also performed to examine the potential revenue impacts due to uncertainties in different data inputs under existing and proposed structures.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00064-1.pdf

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Research and Technology Implementation Office

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Research Digest Item 15 A Comprehensive Examination of Heavy Vehicle Emissions Factors SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 476660-00067-4 • 2010

This report summarizes the findings from reviewing the literature on several topics that are related to heavy vehicle emissions including engine and fuel types, vehicle technologies that can be used to reduce or mitigate vehicle emissions, the factors that affect vehicle emissions, vehicle emissions modeling, and current and future policy requiring accurate accounting of heavy vehicle emissions. The pollutants present in diesel exhaust are known to have undesirable effects on both human health and the environment. There are many engine and fuel alternatives for current and prospective vehicle owners to consider that have differing effects on a vehicle’s pollutant output. In addition, new technologies, such as diesel particulate filters, auxiliary power units, and selective catalytic reduction, are being used in the production of new vehicles, and can often be installed on used vehicles, to reduce emissions and/or improve fuel economy. Accurate heavy vehicle emissions modeling is important in forming policies designed to reduce pollutants from heavy vehicle operation at both the vehicle and regional level. Such policies can include capand-trade schemes, carbon taxing, and road user charging. All of these policy types have been implemented in the European Union to varying degrees, but only some have been implemented in the United States. However, all of these are now being considered in the U.S., and could be implemented in the future.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00067-1.pdf

Item 16 Predicting the Incremental Effects on Transit Ridership Due to Bus-On-Shoulder Operations SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 476660-00073-1 • 2010

Bus-On-Shoulder (BOS) operations are an extremely effective method for increasing the quality of a bus service; allowing for a bus to use a freeway shoulder as a bypass lane not only decreases bus travel time but also increases the bus service’s overall performance. BOS has also been found to increase bus ridership. The modern BOS system began in the Minneapolis-Saint Paul area almost 20 years ago. Using the extensive data available from MinneapolisSaint Paul, ridership changes due to BOS operations were explored. The data showed that with 90% confidence, ridership will increase by at least 4.5% and as much as 14.3%. This report explores how the citizens of Austin, Texas would respond to a BOS operation on local freeways. A stated preference survey was administered to a sample of Austin commuters. It was determined that potential riders would desire a time savings of 7 or more minutes.

Typically, it is challenging for persons to accurately predict time savings, therefore it was concluded that, for a BOS operation to be successful, it was necessary for there to be a perceived time savings.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00073-1.pdf

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Research and Technology Implementation Office

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Research Digest Item 17 Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation SOUTHWEST REGION UNIVERSITY TRANSPORTATION CENTER (SWUTC) / UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

SWUTC/10/ 476660-00074-1 • 2010

Traveler trip length has for years been used as a fundamental indicator of the best mix of transit modes and user perceptions of travel cost for transit versus auto. This study examines traveler trip lengths across transit modes, work trip duration frequency distributions and mode share distributions in 7 major cities, 8 Combined Statistical Areas and one Metropolitan Statistical Area and found the effect of increasing population and transit mode variety on work trip travel time and travel distance.

A traditional hierarchy of transit modes arranged by traveler trip length might include local bus, light rail, rapid rail (heavy rail) and commuter rail (regional rail). Based on NTD data, the average trip length for these four modes are: local bus (4.6 miles), light rail (3.9 miles), heavy rail (6.3 miles), and commuter rail (30.1).

Trip Time Frequency Distributions for home-based work trips in all major cities selected in this study followed the same pattern except in New York, NY. In virtually all cities from 1990 to 2005, frequencies decreased in all categories less than 30 minutes and increased in categories greater than 30 minutes. Meanwhile, Trip Time Frequency Distributions for home-based work trips in all selected MSAs also followed the same pattern. These results contradicted our assumption that cities or MSAs with different urban forms or transit history might have different Trip Length Frequency Distributions (TLFDs) and showed that at an aggregated level, there is no statistically significant difference among TLFDs for work trips in the selected areas.

Average work trip length for all the 50 MSAs in National Household Travel Survey data also showed that travel time and travel distance for home-based work trips in all selected MSAs are very similar. Also, from the linear regression functions with trip length as dependent variable, it can be seen that work trip time and distance tend to increase with increasing population, work trip time and distance tend to increase also as the number of transit modes increase.

Full-text PDF of this report is available for free download from: http://swutc.tamu.edu/publications/technicalreports/476660-00074-1Abstract.htm

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Research and Technology Implementation Office

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