Bridges

Cover of Development of Marginal Costs for Heavy Vehicle Bridge Usage
Development of Marginal Costs for Heavy Vehicle Bridge Usage
  • Publication no: AP-R407-12
  • ISBN: 978-921991-31-8
  • Published: 27 June 2012

This report develops approaches that estimate the marginal cost (MC) of bridge wear for heavy vehicle usage and estimates the availability and reliability of the data needed to use these approaches. Two approaches were examined. The first was an engineering approach based on the life-cycle costs (rehabilitation/capital and maintenance) of bridge wear at a given level of heavy vehicle traffic. The second was an econometric approach based on historical bridge expenditure (rehabilitation/capital and maintenance) and heavy vehicle bridge usage data. Both approaches determine a bridge wear cost relationship with heavy vehicle bridge usage from which the MC of bridge wear can be derived.

A methodology to estimate both the short-run marginal cost (SRMC) and the long-run marginal cost (LRMC) was defined using the engineering approach. The methodology relies on the provision of adequate, accessible and reliable traffic and cost data, and the estimation of fatigue life.

The econometric approach has the potential to estimate SRMC and LRMC, although this approach has the limitation that it may not reliably make these estimates for load increases beyond those captured by historical cost and traffic data due to the assumptions needed to make these estimates.

  • 1.1. Background
  • 1.2. Aims and Scope of Study
    • 1.2.1. Items Out of Scope
  • 1.3. Literature Review
    • 1.3.1. Previous Australian Studies
    • 1.3.2. Cost Impact Studies
  • 2.1. Discussion
  • 2.2. Marginal Costs as the Basis for Pricing
  • 3.1. Discussion of Methodology Parameters
    • 3.1.1. Parameters to Describe Bridge Wear
    • 3.1.2. Short-run vs. Long-run Marginal Costs
  • 3.2. Summary of Factors Affecting Bridge Costs
    • 3.2.1. Factors Affected by Heavy Vehicle Mass and Volume
    • 3.2.2. Factors Affected by Environmental Aspects
    • 3.2.3. Factors Affected by Interactions between Environment and Traffic
    • 3.2.4. Bridge Component Condition
  • 3.3. Grouping Marginal Costs
  • 4.1. Methodology Overview
  • 4.2. Methodology
    • 4.2.1. Estimation of Average Birth Year
    • 4.2.2. Estimation of Past and Future Truck Loading Distributions
    • 4.2.3. Estimation of Additional Maintenance Costs
    • 4.2.4. Estimation of Additional Upgrade Costs
  • 4.3. Data Requirements of the Engineering Approach
  • 5.1. General Overview
  • 5.2. Methodology
  • 5.3. Data Needs and Availability
    • 5.3.1. Data Requirements for the Econometric Approach
  • 6.1. Questionnaire
    • 6.1.1. Data Requirements – Expenditure Data
    • 6.1.2. Data Requirements – Heavy Vehicle Road Use
    • 6.1.3. Information Relating to the Engineering Approach
  • 6.2. Summary of Questionnaire Responses
  • 6.3. Viability of the Engineering and Econometric Approaches
    • 6.3.1. Engineering Approach
    • 6.3.2. Econometric Approach
    • 6.3.3. Conclusions
  • 6.4. Project Implementation and Costs
    • 6.4.1. Data Exploration and Review
    • 6.4.2. MC Estimation using the Engineering Approach
    • 6.4.3. MC Estimation using the Econometric Approach
  • 7.1. Conclusions – Stage 1
    • 7.1.1. MC Estimation using the Engineering Approach
    • 7.1.2. MC Estimation using the Econometric Approach
    • 7.1.3. Issues to be Considered before Proceeding with Stage 2
  • 7.2. Stage 2 Strategy
    • 7.2.1. Data Exploration and Review
    • 7.2.2. MC Estimation using the Engineering Approach
    • 7.2.3. MC Estimation using the Econometric Approach