Download - Calculating the Cost of Road Wear on Local Roads Mark Bondietti Riaan Burger October 2013
Calculating the Cost of Road Wear on Local Roads
Mark BondiettiRiaan Burger
October 2013
Contents
• Background• Methods• Marginal Costs• Catalogue Method• Case Study• FAMLIT• Future Work
Background
• Local Governments seek mechanisms to quantify cost of road wear
• Impact of road wear much higher on local roads• Various methods have been tried – too
expensive, specialised skills.• Seek simple method
Methods for Evaluating the Cost of Road Wear
• Routine Maintenance Determination• Evidence Based Reporting• Pavement Design Approach• Single Marginal Cost• Catalogue of Marginal Costs
MRWA Policy
• For vehicles operating 23.5 t triaxles the charge will be 0.4 cents per tonne per kilometre of payload (over and above the initial 300,000 tonne per annum).
• For alternative mass limits the charge will be determined on the basis of 5.5c per additional ESA.km
• Is this sufficient for Local Roads?
Pri
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req
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r c
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t re
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PortFarmJourney from Farm or Mine to Port
Major Main Road
State Rural Highway
Minor Main Road
Regional Local Road
Minor Local Road
Price Charged
Road Wear Cost – Farm or Mine to Port
Urban Highway or Freeway
Determine Vehicle type and
loading
Calculate Equivalent
Standard Axles for Transport Task
Determine road type and distance of transport route
• Road pavement structure would preferably be required however this can be inferred from the road classification
Determine appropriate
marginal cost for road type
Calculate cost of road wear
• Cost of road wear = ESA x Marginal Cost x Distance
Calculating the Cost of Road Wear on Local Roads
Calculation Example: Yalgoo – Ningham Road
• ESA / payload tonne = 0.18
Therefore 1.4 m tonne = 252 000 ESA
• For rural collector 30c / SAR km
For Arterial = 5c / SARkm(Austroads)
Using 7c:
Therefore cost = 252000 x 58.1 x 0.07
= $1 024 884 per annum
Quad Road TrainConcessional Load – 23.5t per triaxle
58.1 km task1 400 000 tonne/ annum
Sealed Rural Collector / Arterial Road
FAMLIT
• Quick description– Background– Model description
• Results of pilot study for WALGA
FAMLIT Background
• FAMLIT is a sealed pavement life-cycle costing analysis tool (Austroads project AT1165)
• Other similar tools are:– HDM-4– PLATO
• FAMLIT was used in Austroads project AT 1394 due to its relatively simple input data requirements
“Preliminary methodology for estimating cost implications of incremental loads on road pavements”
FAMLIT Description
• Life cycle costs are calculated over a 50-year analysis period
• Routine and periodic maintenance costs are combined in a constant annual value for a given traffic load
• Structural works are triggered based on condition• FAMLIT implementation used two models for triggering
structural works:– Rutting/roughness model– Pavement strength model
• Model parameters/coefficients are similar to those used in the ROMAN II dTIMS set-up
FAMLIT Results
• Traffic is applied to pavement and condition modelled over time
• Routine and periodic treatments are constant costs over analysis period
• When condition triggers, structural work costs are calculated and condition reset to pre-determined levels
• Total cost for each loading scenario is converted to Equivalent Annual Uniform Cost (EAUC)
• For each pavement/climate scenario the EAUCs for the different load scenarios are plotted and a straight line fitted
• Marginal Cost is the slope of the line
y = 71938.011x + 1144.000 R² = 0.995
y = 18437.304x + 1528.658 R² = 0.976
y = 16942.635x + 2778.694 R² = 0.986
0
2000
4000
6000
8000
10000
12000
14000
16000
0 0.05 0.1 0.15 0.2 Annual million equivalent axles (MESA)
Thornthwaite = 10 CBR = 12
Rural Access
Rural Collector
Rural Arterial
Linear (Rural Access)
Linear (Rural Collector)
Linear (Rural Arterial)
EUAC
($)
Future Work
• Refine input data– Divide state into regions– Obtain unit rates applicable to regions– Refine pavement strength model– Refine pavement types and composition for
regions• Produce simple to use tool for Local
Governments– Form baseline of discussion regarding
compensation with industry operators
Questions