Asset Management Plan – Unsealed Roads
Unsealed 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 (which provides Council with a clear direction and goal for managing the community's $1.185 billion (as at June 2010) worth of assets).
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Hierarchy of Unsealed Roads
The unsealed 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: Collector Unsealed
Low to moderate-capacity road which serve to move traffic from local streets to arterial and sub-arterial roads For example Keajura Rd, Dunns Rd
Local Major Unsealed
Have the lowest speed limit, and carry low volumes of traffic to collectors or sub arterial. For example Humula 8 Mile Rd, Westbrook Rd, Church’s Plain Rd
Local Minor Unsealed
Have the lowest speed limit and carry lowest volumes of traffic to local major or collector roads. For example Livingstone Gully Rd, Pine Gully Rd, Shepherds Siding Rd Unsealed laneways with access to multiple sites. For example 13 Mile Reserve Rd, Borambola North Rd.
Multi Access Unsealed Access Unsealed
Category for access roads to a single site. For example Captain Cook Dr, Humula St, Wheel of Fortune Rd
Other Maintained Unsealed
Similar category to multi-access unsealed with lower volumes. For examples are Angels Ln, Tywong St
Unmaintained
Lowest category of unsealed road. Roads that are very infrequently used and are not annually maintained.
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Unsealed Roads The following map details the unsealed road hierarchy across the Wagga Wagga Local Government Area (LGA).
Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 3
Unsealed Roads 2
Current Asset Base
The condition of Council’s assets has been audited as part of the asset inspection regime, rated against the asset condition reference sheet and captured in Council’s electronic mapping system. The condition of all Council’s assets is rated from excellent to very poor. The colours on the following map indicate the condition of the asset, as detailed in the below table 1 2 3 4 5
Excellent Good Average Poor Very Poor
Dark Green Green Yellow Orange Red
Map – Condition The following table highlights the proportion of the unsealed road network in each condition from excellent to very poor across the Wagga Wagga Local Government Area (LGA). Excellent Good Average Poor Very Poor
2.7% 54% 24% 9.7% 9.6%
165,714m2 3,367,559m2 1,499,885m2 602,401m2 597,197m2
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Unsealed Roads The following map indicates the condition of the unsealed road network from excellent to very poor across the Wagga Wagga LGA.
Size of the Network Council owns and maintains approximately 1,106km of unsealed roads.
Challenges of the Network The unsealed road network is considerable in size and is spread across the entire Wagga Wagga LGA. There are some unsealed roads which are linkages from rural areas into the Wagga Wagga urban area and the nine rural villages, the traffic volumes on these roads can be significant. Other rural roads are used by a small number of people and have very low traffic volumes. Both high and low traffic volumes on unsealed roads present maintenance challenges. The condition of unsealed roads with a high traffic volume can decrease rapidly, especially in times of high rain fall. The unsealed roads which service only one or two rural properties have very low usage rates and the cost to maintain them is the same as a high use road. In addition some rural roads in the Wagga Wagga LGA have seasonal peak traffic flows, for example in the grain harvest a lot of heavy vehicles use unsealed roads which for the rest of the year have low traffic volumes.
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Unsealed Roads Storm events and heavy rain strip gravel from an unsealed road. This can make the road rough or slippery and can increase the rate of deterioration. In periods of high rainfall the time required and cost to replace the gravel present a challenge to Council. Due to the quantity and spread of the unsealed roads across the Wagga Wagga LGA moving work crews and machinery around the network is a challenge. It is difficult to source high quality product locally to construct an unsealed road. If poor quality material is used to maintain or renew an unsealed road the rate of deterioration will increase. Drainage adjacent to the unsealed road which is not maintained effectively presents challenges to the unsealed road.
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Unsealed Roads 3
Condition Assessment
Condition Ratings Reference Sheet The condition of unsealed roads is audited against a rating scale which ranges from excellent to very poor. This scale is used as the basis of all assessments of unsealed roads by Council’s Surveillance Team. The rating scale forms the Condition Rating Reference Sheet below.
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Unsealed Roads Risk and Condition Rating 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 road classification and estimated traffic volumes. The following table details the Risk Rating Indicators for the unsealed road network. Unsealed Roads Risk Rating Indicators - Based on Road Type Weighting 1.4 1.3 1.2 1.1 1.0
Road Type/Traffic Volume Collector Unsealed Local Major Unsealed Local Minor Unsealed Multi Access and Access Unsealed Other Maintained
The second stage of the process considers the Condition Rating Indicators. The following indicators are considered for each section of unsealed road:
potholing corrugation thickness of gravel cover and boniness (size of rock, fines blown away)
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Unsealed Roads The more deteriorated a section of unsealed road is, the higher the rating for cracking, skid resistance and distortion. Each section of unsealed road is rated against the Condition Rating Indicators detailed in the below table. Unsealed Roads Condition Rating Indicators Score
Potholing
Corrugation
Thickness of Gravel Cover
Boniness
1
No potholes
No corrugation
Excellent cover
No boniness
2
Minor potholing
Minor corrugation
Good cover
Minor boniness
3
Potholes cover less than 10%
Significant corrugation
Average cover
Boniness cover less than 10%
4
Potholes cover between 11-30%
Major corrugation
Poor cover
Boniness cover between 11-30%
5
Potholes cover more than 30%
Extreme corrugation
Very poor cover
Boniness cover more than 30%
The results of the Risk and Condition Rating Indicators analysis are combined to give an individual asset or section of the asset a Works Schedule Priority Rating. For example a section of unsealed road could be rated as follows: Unsealed Road XYZ Potholing (P) 4 Corrugation (C) 4 Thickness of Gravel Cover (GC) 5 Boniness (B) 3 Road Type (RT) 1.1 (Multi Access and Access Unsealed) Works Schedule Priority (P + C + GC + B)RT Rating Formula Works Schedule Priority (4 + 4 + 5+ 3)1.1 = 17.6 Rating The Work Schedule Priority Ratings for sections of unsealed roads 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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Unsealed Roads Intervention Levels To guide Councilâ&#x20AC;&#x2122;s response to customer requests a set of reactive triggers has been developed for each asset category. These triggers are called intervention levels and include expected response times. The following tables detail the intervention levels and response times for maintenance of the unsealed road network. Unsealed Roads Intervention Levels Potholes <75 mm deep or <300mm diameter
Corrective action taken within 2 months
Potholes >75 mm deep or >300mm diameter
Corrective action taken within 2 weeks
Minor rutting/corrugation
Monitor only
Moderate to major rutting/corrugation
Corrective action taken within 2 months
Missing guideposts
Corrective action taken within 1 month
Loss of gravel cover
Corrective action taken based on the severity of gravel loss
Damaged guardrail
Corrective action taken within 1 week
Missing sign
Corrective action taken within 2 weeks
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, sealed road and unsealed 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 Councilâ&#x20AC;&#x2122;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 unsealed 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 occur to the network, for example when maintenance events like shoulder grading the
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Unsealed Roads 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 unsealed 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 unsealed road network should be carried out according to the following inspection hierarchy: Road Classification
Inspection/Routine Maintenance Trips
Condition Assessment
Collector Unsealed
Once per 3 months
Every 2 years
Local Major Unsealed
Once per 6 months
Every 2 years
Local Minor Unsealed
Once per 6 months
Every 2 years
Multi Access Unsealed
Once per year
Every 2 years
Other Maintained Unsealed
Once per year
Every 2 years
Unmaintained
Nil
Every 2 years
Risk Management Inspection Regime Due to the size and usage of the unsealed road network, a Risk Management 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 and corrugation
Risk Management 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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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.
Costs occur in each phase of the asset life cycle. It is important to attribute these life cycle costs to each phase to allow for effective decision making about how the asset will be managed. The life cycle costs of assets include:
initial capital investment operation and maintenance refurbishment and renewal administration, overheads and taxes depreciation capital use rate charges or rate of return and disposal of the asset at the end of its useful life
The initial capital or investment cost of a new asset is a significant cost and often dominates the decision as to whether to acquire the asset or expand the infrastructure network. However, it is important to include all the costs associated with each phase of the asset life cycle, including ongoing operation and maintenance, future renewal and disposal.
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Unsealed Roads Target Maintenance Events The following table details the target maintenance events associated with the unsealed roads network annually. Unsealed Roads Target Maintenance Events Event Target Maintenance Events per Year Weed spraying
Twice per year
Slashing
Twice per year
Sapling Control
Once per year
Tree Pruning
Once per year
Grading High Priority (collector, local major and all urban unsealed)
Twice per year
Drainage Reshaping High Priority (collector, local major and all urban unsealed)
Twice per year
Grading Medium Priority (local minor, multi access and all village unsealed)
Once per year
Drainage Reshaping (local minor, multi access and all village unsealed)
Once per year
Grading Low Priority (access and lower)
Once per year
Drainage Reshaping (access and lower)
Once per year
Renewal A detailed work plan for the renewal of the unsealed road network is developed annually to support this Asset Management Plan. This renewal program is prioritised based on condition and risk.
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 for all asset types.
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Level of Service
The Asset Management Plan for 2011 has been developed based on data collation, research outcomes and the results of Councilâ&#x20AC;&#x2122;s internal stakeholder engagement process. The next stage of the process is to ask the community to identify which asset condition is satisfactory to them. This will begin with an extensive community consultation process. The consultation will be in the form of a community survey which will be conducted online, at community gatherings, through focus groups and stakeholder meetings. The survey will use new technology, be based on images and a simple selection process. The outcomes of the consultation will form the foundation for true community engagement to occur in relation to the management of infrastructure across the Wagga Wagga LGA, in particular the development of agreed levels of service, supported by Council and the community. As Council gathers data from the community about the level of service for each asset category the outcomes will be integrated into the Asset Management Plan. Until the outcomes of the community engagement are known Council will provide costings to achieve an average condition for each asset category and use this as the satisfactory level of service.
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Financial Considerations
The following graph details the proportion of the unsealed road network in each condition.
Council’s current liability in relation to the infrastructure network is the sum of all asset units which have a condition rating of poor and very poor. The current liability of the unsealed road network is estimated to be $3,354,500 (in 2010 dollars). The following table provides the details of the unsealed road network current liability.
Asset Condition 4 – Poor 5 – Very Poor Total Current Liability
Amount 110.3km 112.2km 224.2km
Estimated Cost in 2010 dollars $1,654,500 $1,700,000 $3,354,500
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Unsealed 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 unsealed roads network is estimated to be $2,959,836 (in 2010 dollars). It is a first principle estimate and is expected to vary as Council continuously develops its asset management process and strategies. The following table provides further details of the maintenance costs associated with maintaining the unsealed road network each year: Unsealed Road Network Annual Maintenance Costs Event Maintenance Costs per Year Weed spraying $37,084 Slashing $442,400 Sapling control $27,423 Tree pruning $339,261 Major fettling $34,865 Minor fettling $73,771 Guidepost maintenance $123,518 Guardrail maintenance $10,240 Grading $1,494,725 Drainage reshaping $320,298 Signs $56,250
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 unsealed road network should increase as it expands. Required Increase to Maintenance Budget for Additional Unsealed Roads Category Maintenance Costs per Year per m2 Maintenance - high priority urban unsealed road $5.11 Maintenance - high priority rural unsealed road $4.64 Maintenance - medium priority rural unsealed road $2.93 Maintenance - low priority rural unsealed road $2.93
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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.
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