Recent Austroads work (TP1349) has highlighted the need to improve the vehicle operating costs (VOC)-road roughness relationship. This report achieves this by conducting a literature review of overseas and local models to establish whether overseas models and recent Australasian work have improved the link between VOC and road roughness. The VOC-road roughness relationship is reviewed in terms of the VOC components: fuel consumption, repair and maintenance costs, tyre costs, lubricating oil costs and vehicle depreciation. For each component, Australian findings are compared with those of the overseas models. Modelling considerations for Australia are also discussed. The report provides information on the VOC-roughness relationship in a single source, which assists practitioners in keeping updated on developments in VOC research. Three outcomes are achieved: 1) The international literature review has succeeded in establishing that a scientific relationship (in terms of the directional impact) between each VOC component and roughness exists. 2) Harmonisation ensures similar road user cost (RUC) estimates are used across models and scenarios. Australian jurisdictions can maintain their models whilst reconciling results with harmonised parameters. 3) A quantifiable relationship between roughness and each VOC component can be reached provided modelling considerations (stated for each VOC component) are applied in Australia. (Author/publisher)
Abstract