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Asset Management Plan – Unsealed Roads

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Page 1: Unsealed Roads

Asset Management Plan –Unsealed Roads

Page 2: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 2

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).

1 Hierarchy of Unsealed RoadsThe 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:

CollectorUnsealed

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 MajorUnsealed

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 MinorUnsealed

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

Multi AccessUnsealed

Unsealed laneways with access to multiple sites. For example 13 Mile Reserve Rd, Borambola North Rd.

Access Unsealed Category for access roads to a single site. For exampleCaptain Cook Dr, Humula St, Wheel of Fortune Rd

Other MaintainedUnsealed

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.

Page 3: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 3

The following map details the unsealed road hierarchy across the Wagga Wagga Local Government Area (LGA).

Page 4: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 4

2 Current Asset BaseThe 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 Excellent Dark Green

2 Good Green

3 Average Yellow

4 Poor Orange

5 Very Poor Red

Map – ConditionThe 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 2.7% 165,714m2

Good 54% 3,367,559m2

Average 24% 1,499,885m2

Poor 9.7% 602,401m2

Very Poor 9.6% 597,197m2

Page 5: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 5

The following map indicates the condition of the unsealed road network from excellent to very poor across the Wagga Wagga LGA.

Size of the NetworkCouncil owns and maintains approximately 1,106km of unsealed roads.

Challenges of the NetworkThe 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.

Page 6: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 6

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. Inperiods 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.

Page 7: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 7

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.

Page 8: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 8

Risk and Condition Rating IndicatorsCouncil 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 Road Type/Traffic Volume

1.4 Collector Unsealed

1.3 Local Major Unsealed

1.2 Local Minor Unsealed

1.1 Multi Access and Access Unsealed

1.0 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)

Page 9: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 9

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 coverless than 10%

Significant corrugation

Average cover

Boniness cover less than 10%

4 Potholes cover between 11-30%

Major corrugation

Poor cover Boniness cover between11-30%

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 Rating Formula

(P + C + GC + B)RT

Works Schedule Priority Rating

(4 + 4 + 5+ 3)1.1 = 17.6

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.

Page 10: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 10

Intervention LevelsTo guide Council’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 RegimeFor 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 RegimeThe 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-sitescheduled 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

Page 11: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 11

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 RegimeDue 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.

Page 12: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 12

4 Life Cycle ManagementLife cycle management details how Council plans to manage and operate the asset category at the agreed level of service while minimising life cycle coststhroughout 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.

Page 13: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 13

Target Maintenance EventsThe 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

RenewalA 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.

DisposalCurrently, 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.

Page 14: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 14

5 Level of ServiceThe Asset Management Plan for 2011 has been developed based on data collation, research outcomes and the results of Council’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.

Page 15: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 15

6 Financial ConsiderationsThe 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 Amount Estimated Cost in 2010 dollars

4 – Poor 110.3km $1,654,500

5 – Very Poor 112.2km $1,700,000

Total Current Liability 224.2km $3,354,500

Page 16: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 16

Projected Annual Maintenance CostsFor Council to achieve the target maintenance events as detailed in Section 4of 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

Page 17: Unsealed Roads

Unsealed Roads

Wagga Wagga City Council // Asset Management Plan // Unsealed Roads // Page 17

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.

Page 18: Unsealed Roads