Asset Management Plan – Sealed Roads
Sealed Roads This Supporting Section should be read in conjunction with Council’s Asset Management Plan, the Asset Management Policy (which sets out Council's philosophy of asset management) and Council’s Asset Management Strategy and Strategic Direction documents (which provides Council with a clear direction and goal for managing the community's $1.178 billion (as at June 2012) worth of assets). These documents can be found at http://www.wagga.nsw.gov.au/city-of-wagga-wagga/engineering-services/assetmanagement-introduction/asset-management-plan . This is the second edition of the Sealed Roads Supporting Section of the Asset Management Plan and is based on the most current data available as at September 2012.
1
Hierarchy of Sealed Roads
The sealed road network is categorised into a hierarchy, which is based on traffic volumes. The hierarchy allows informed decisions to be made relating to inspections, maintenance and renewal. The following table details the hierarchy: Highway
Very major road connecting two or more destinations with very high traffic volume and highest speed limits. These roads are not Council controlled. For example Hume, Sturt and Olympic Highways.
Arterial Regional
High-capacity urban or regional road. For example Coolamon Rd, Bourke St, Lake Albert Rd.
Sub Arterial Sealed
Moderate-capacity urban road which lead to arterial roads. For example Fernleigh Rd, Mitchelmore St, Morgan St.
Collector Sealed
Low to moderate-capacity road which moves traffic from local streets to arterial and sub-arterial roads. For example Coleman St, Forsyth St, Dalman Parkway.
Local Major Sealed
Have lowest speed limit and carry low volumes of traffic to collectors or sub arterial roads. For example Bulolo St, Malaya Dr, East Lake Dr.
Local Minor Sealed
Have the lowest speed limit and carry lowest volumes of urban traffic. These are most urban streets in every suburb.
Multi Access Sealed
These tend to be laneways with access to multiple sites. Examples are most of the laneways in the CBD.
Access Sealed
Lowest road category for access roads to a single site. For Example Captain Cook Dr, Humula St.
The following map indicates the sealed road hierarchy of the Wagga Wagga Local Government Area (LGA).
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Sealed Roads Road Hierarchy Map as at June 2012
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Sealed Roads 2
Current Asset Base
The following table highlights the proportion of the sealed road network in the Wagga Wagga Local Government Area (LGA) in each condition ranging from excellent to very poor as at June 2012 compared to June 2010. Network 2010
Network 2012 2
7.48%
654,709 m2
Excellent
14.7%
1,284,618 m
Good
43.7%
3,831,258 m2
39.57%
3,465,388 m2
Average
30.9%
2,708,377 m2
37.59%
3,292,112 m2
Poor
8.5%
747,336 m2
12.90%
1,129,727 m2
Very Poor
2.2%
193,328 m2
2.46%
215,100 m2
TOTAL
8,764,917 m2
8,757,036 m2
The colours in the above table appear in the following maps and indicate the condition of each section of sealed road in the Wagga Wagga LGA.
Rural Sealed Road Network Map as at June 2012
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Sealed Roads Urban Sealed Road Network Map
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Sealed Roads Size of the Network Council owns and maintains a sealed road network totalling 1,169km. These sealed roads range from major sub-arterial to minor access roads. The size of the network has remained almost constant since 2010. The value of this infrastructure network is estimated to be $168,559,830 (in 2012 dollars).
Challenges of the Network The size of the sealed road network in the Wagga Wagga LGA presents challenges. Over half of the sealed road network is in the rural areas of the Wagga Wagga LGA and the distance involved means the logistics and costs of moving work crews and machinery around the network can be challenging. As with many areas across the State, the sealed roads in the Wagga Wagga LGA are ageing. The maintenance required to keep infrastructure to a satisfactory condition often increases as the asset ages. The ageing network sees maintenance costs of sealed roads being a significant cost to Council. It is often difficult to source high quality construction materials locally. If lower quality materials are used to construct roads the lifespan of the pavement, in particular is decreased considerably. The ingress of water increases when the seal fails, causing the condition of the pavement to deteriorate rapidly. In the urban area, the condition of kerb and gutter has a significant impact on the condition of the sealed road adjacent to it. If the kerb and gutter is not moving the water into the stormwater system quickly it ponds on the road, increasing the risk of water ingress. As the city and surrounding areas expand the usage of local roads increases and there is a risk that the vehicle movements per day will exceed the capacity of the road. This presents a challenge in the management of the network and the future development of the city.
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Sealed Roads 3
Condition Data
Condition Ratings Reference Sheet The condition of the sealed roads network is audited against a rating scale which ranges from excellent to very poor. This scale is used as the basis of all assessments of the sealed roads network by Council’s Surveillance Team. The rating scale forms the Condition Rating Reference Sheet below.
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Sealed Roads Risk and Condition Ratings Indicators Council also uses Risk and Condition Rating Indicators to determine a prioritised works schedule for the maintenance, renewal and replacement of large asset categories. These indicators are used in addition to the Condition Ratings Reference Sheet to enable further analysis of the worst sections of the asset class. The indicators are used to develop an overall Works Schedule Priority Rating for each individual asset or section of an asset. The first stage considers the risk that the condition of the asset poses to the community based on location, road classification and estimated pedestrian and traffic volumes. The following table details the Risk Rating Indicators for the sealed roads network. Sealed Roads Risk Rating Indicators- Based on Location and Road Type Weighting Location/Estimated Traffic Volume 1.2 Commercial Precincts (Central Business District, shopping malls) 1.1 Community Precincts (schools, churches, hospitals, clubs, community centres) 1.0 Residential Areas Weighting 1.3 1.2 1.1 1.0
Road Type/Traffic Volume Arterial Road or Highway Sub Arterial/Regional Road Collector/Distributor Road Residential Road
The second stage of the process considers Condition Rating Indicators. The following indicators are considered for each section of sealed road: • • • • •
condition cracking skid resistance potholes and distortion (roughness)
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Sealed Roads The more deteriorated a section of sealed road is, the higher the rating for cracking, skid resistance and distortion. Each section of sealed road is rated against the condition rating indicators detailed in the below table. Score
Cracking
Skid Resistance
Distortion
Potholes
1
No cracks
Excellent grip
No distortion
No potholes
2
Isolated fine cracking
Good grip
Slight distortion
Minor potholing
3
Cracking less than 5%
Average grip
Minor distortion
Potholes cover less than 10%
4
Cracking less than 620%
Poor grip
Uneven surface
Potholes cover between 11-30%
5
Cracking greater than 20%
Very poor grip
Very uneven and rough surface
Potholes cover more than 30%
The results of the condition and risk rating indicators are combined to give an individual asset or section of the asset a works schedule priority rating. For example a section of sealed road could be rated as follows:
Sealed Road XYZ Cracking (C)
4
Skid Resistance (SR)
4
Distortion (D)
5
Location (L)
1 (Residential)
Road Type (RT)
1.1 (Collector)
Works Schedule Priority Rating Formula
(C + SR + D)L x RT
Works Schedule Priority Rating
(4 + 4 + 5)1 x 1.1 = 14.3
The work schedule priority ratings for sections of sealed road are then ranked from highest to lowest to produce prioritised schedule of works for maintenance, replacement and renewal of the network.
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Sealed Roads Condition and Risk Inspection Regime For large asset categories of high risk, Council implements two separate inspection regimes, based on condition and risk. These inspection regimes have been developed for the footpath, unsealed road and sealed road networks. These particular assets require this level of inspection due to the size and the high usage of each network. These networks have been identified as high risk to Council. The two inspection regimes are detailed below. Condition Assessment Inspection Regime The Condition Assessment Inspection Regime is developed for all Council’s infrastructure assets and is designed to audit the condition of each section of the asset against the Condition Ratings Reference Sheet. An on-site scheduled condition assessment audit of the sealed road network will be conducted every two years. The inspection regime also includes reactive condition assessment audits which are conducted throughout the network when there are changes to the network, for example when maintenance events like shoulder grading occur the condition rating will change and the inspection will capture this change to the network. The condition assessment inspections are in the form of an on-site GPS audit for all sealed roads in the Wagga Wagga LGA. All audit results, data variations and updates to the network are captured in Council’s electronic mapping system (ArcGIS). The inspection routine of the sealed road network should be carried out according to the following inspection hierarchy:
Road Classification
Routine Inspection
Condition Assessment Audit
Arterial
Once per month
Every 2 years
Sub-arterial
Once per 3 months
Every 2 years
Collector
Once per quarter
Every 2 years
Local – major
Once per 6 months
Every 2 years
Local – minor
Once per 6 months
Every 2 years
Multi access
Once per year
Every 2 years
Access
Once per year
Every 2 years
Other
On request
Every 2 years
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Sealed Roads Risk Inspection Regime Due to the size and usage of the sealed road network, a Risk Inspection Regime has also been developed for this infrastructure asset and will be conducted separately to the condition assessment audit. The risk management inspections will identify and map: • • • • • • •
road potholes and major defects missing guideposts missing signs damaged guardrails dangerous trees roadside vegetation and shoulder drop-offs from the edge of the seal to the gravel shoulder
Risk Inspections are undertaken in response to customer requests, on a needs basis and where the asset degrades due to un-foreseen or unusual circumstances, like a storm event. These inspections are done onsite by trained Surveillance Officers and the results are captured in the ArcGIS system.
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Sealed Roads 4
Life Cycle Management
Life cycle management details how Council plans to manage and operate the asset category at the agreed level of service while minimising life cycle costs throughout the useful life of the asset. For most local government assets there are four key phases to the life cycle, namely: acquisition, operation and maintenance, renewal, and disposal. Further information about life cycle management and the processes used by Council to manage each stage of the life cycle can be found in the Asset Management Plan at http://www.wagga.nsw.gov.au/city-of-waggawagga/engineering-services/asset-management-introduction/assetmanagement-plan .
Acquisition The acquisition of sealed roads occurs through the expansion of the network through development in most cases. The network can also expand as a result of existing roads being widened, as the network is measured in square metres. When a section of sealed road is built or widened details are recorded in Council’s asset management system and the new asset is included in the appropriate inspection regimes.
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Sealed Roads Maintenance Target Maintenance Events The following table details the target maintenance events associated with the sealed roads network annually. Sealed Roads-All Roads Target Maintenance Events Event
Target Maintenance Events per Year
Tree Pruning
Once per year
Weed spraying
Twice per year
Slashing
Twice per year
Sapling control
Once per year
Shoulder grading
Every 2 years
Drainage Reshaping
Every 2 years
Shoulder grading
Every 3 years
Drainage Reshaping
Every 3 years
Shoulder grading
Every 4years
Drainage Reshaping
Every 4 years
Arterial regional and all sealed roads in the urban area without kerb and gutter Sub arterial and collector roads outside the urban area All other sealed roads outside the urban area
Unscheduled Maintenance To guide Council’s response to registered requests in Council’s Customer Request System, reactive triggers (based on the level of risk) have been developed for each asset category. These triggers include intervention activities and target response times. Whilst Council aims to achieve these target response times, situations can arise that hamper Council’s efforts and response times may be extended for reasons including, but not limited to resource availability, excessive workloads and emergency events which impact the network.
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Sealed Roads The following table details the reactive triggers, intervention and target response times for unscheduled maintenance of the sealed road network. Sealed Roads Target Intervention for Unscheduled Maintenance Reactive Trigger
Intervention
Target Response Times
Potholes less than 75 mm deep, OR less than 300mm diameter
Corrective action
within 2 weeks
Potholes greater than 75 mm deep, OR greater than 300mm diameter
Corrective action
within 2 days
Shoulder drop-offs less than 100mm
Corrective action
within 2 weeks
Shoulder drop-offs greater than 100mm
Corrective action
within 3 days
Missing Guideposts
Corrective action
within 1 month
Missing signs
Corrective action
within 2 weeks
Damaged guardrails
Corrective action
within 1 week
Shoves < 75mm
Corrective action
within 2 weeks
Shoves > 75mm
Corrective action
within 2 days
Significant cracking
Corrective action
within 1 month
Renewal A detailed works program for the renewal of the sealed road network is developed annually to support this Asset Management Plan. This renewal program is prioritised based on the results of the condition audits. The renewal plan is developed by Council’s Asset Integrity Section based on the data in Council’s asset management system. The renewal plan is recommended to the Business Owner of the sealed road network, who decides the works to be implemented. The implementation of the works program depends on the level of funding available in Council’s budget, as detailed in the Long Term Financial Plan or grant funding received. The renewal of a section of sealed road could be in the form of a complete replacement or the replacement of a component of the road. This level of detail is captured during the condition audits of the network and included in the works program.
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Sealed Roads Once a section of sealed road is renewed the data is captured in Councilâ&#x20AC;&#x2122;s asset management system.
Disposal Currently, Council includes the cost to dispose of an asset in the unit rate of that asset type. As Council moves towards strategic asset management this cost will be captured separately. The Asset Management Plan will be updated to reflect this change as it occurs across the asset types.
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Sealed Roads 5
Level of Service
The level of service for each asset category defines what Council intends to deliver to the community with respect to its assets and the level of service the community can afford. The level of service for each asset category is being developed in the coming years and will be based on community expectations, legislative requirements and internal Council policy. When developed, the level of service for each asset category will focus on how the community experiences the asset (relating to factors such as condition, quality, reliability, responsiveness, sustainability, timeliness, accessibility, cost and functionality) and technical characteristics required to deliver the asset. There is a direct relationship between the level of service provided by an asset and the cost to provide it. As the level of service becomes higher, the cost to provide it also increases. As Council moves towards strategic asset management, Council will consider these two factors in relation to each asset category and for the infrastructure network as a whole. In 2012 the level of service for each asset category is based on the satisfactory condition of the asset, coupled with Councilâ&#x20AC;&#x2122;s target response times and actions for unscheduled maintenance activities as contained in this Asset Management Plan. For more details about the level of service for asset categories please see the Asset Management Plan at http://www.wagga.nsw.gov.au/city-of-waggawagga/engineering-services/asset-management-introduction/assetmanagement-plan.
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Sealed Roads Satisfactory Condition In Councilâ&#x20AC;&#x2122;s first Asset Management Plan of 2011 the satisfactory condition for the sealed road network was set at average. The following graph details the proportion of the sealed road network in each condition. The graph is based on condition data from the asset management system as at 2008/09, 2009/10 and 2011/12.
As indicated on the graph the overall condition of the network has deteriorated since 2008/09. In 2012 there are fewer sealed roads in excellent and good condition than there were in 2008/09 and a greater proportion of the network in average and poor condition. Therefore as the level of service for this asset category is average, the percent of the network not meeting the level of service has increased over the last four years.
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Sealed Roads 6
Financial Considerations
Current Liability Council’s current liability in relation to the infrastructure network is the sum of all asset units which have a condition rating of less than average and are therefore deemed unsatisfactory. The current liability of the sealed road network is estimated to be $14,087,679 (in 2012 dollars), up from $9.3 million in 2010. The following table provides the details of the sealed road network current liability in 2010 and 2012.
Asset Condition 4 – Poor 5 – Very Poor Total Current Liability
Current Liability 2010 Amount Estimated Cost in 2010 dollars 2 740,656 m $7,100,000 2 193,328 m $2,200,000 933,984 m2
$9,300,000
Current Liability 2012 Amount Estimated Cost in 2012 dollars 2 2,262,243 m $ 11,886,955 2 430,200 m $ 2,200,724 2,692,443 m2
$14,087,679
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Sealed Roads Projected Annual Maintenance Costs For Council to achieve the target maintenance events as detailed in Section 4 of this Asset Management Plan, the projected annual maintenance budget for the sealed roads network is estimated to be $5,832,595 (in 2010 dollars). This estimate was developed by Councilâ&#x20AC;&#x2122;s Asset Management Planning and Program Integration Teams in 2010. It is a first principle estimate and is expected to vary as Council improves its asset management process and strategies. The following table provides further details of the maintenance costs associated with maintaining the sealed road network each year (in 2010 dollars).
Sealed Road Network Annual Projected Maintenance Costs Event
Projected Annual Maintenance Costs
Mini stabilising pavement
$1,132,664
Pothole patching
$1,752,991
Crack sealing
$64,000
Guardrail maintenance
$10,240
Tree pruning
$359,507
Street sweeping
$563,333
Weed spraying
$28,735
Slashing
$342,800
Sapling control
$21,249
Guidepost maintenance
$96,069
Shoulder grading
$1,021,801
Drainage reshaping
$215,036
Sign maintenance
$224,250
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Sealed Roads Required Increase to Annual Maintenance Budget per Additional Unit As the asset base increases it is important to ensure that the annual maintenance budget also increases. The following table details how much per unit the annual maintenance budget for the sealed road network should increase as it expands (in 2010 dollars).
Required Increase to Maintenance Budget for Additional Sealed Road Category
Maintenance Costs per Year per m2
Maintenance – high priority urban sealed roads
$5.11
Maintenance – high priority rural sealed roads
$4.72
Maintenance – medium priority rural sealed roads
$4.19
Maintenance – low priority rural sealed roads
$3.92
7
Assumptions
There are some generic assumptions made in the management of assets in Wagga Wagga City Council, these are found in the Asset Management Plan at http://www.wagga.nsw.gov.au/city-of-wagga-wagga/engineering-services/assetmanagement-introduction/asset-management-plan . In addition, the following assumptions have been made in relation to the sealed roads network: • The current liability for the sealed network detailed in this Asset Management Plan does not take into account the damage to the network from the three significant flood events in 2010. The current liability included is based on data collected before these events. The cost of this damage will be included in the next version of the Plan. • The Condition Ratings for the sealed road network are based on a visual inspection of the wearing surface. To date, no technological assessment of the network has been conducted. As Council moves towards strategic asset management these assessments may be conducted.
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