1. Overview and scope of parameter values
This part of the ATAP Guidelines deals with the updating of parameter (unit) values for use by economic evaluation practitioners in Australia jurisdictions as at June 2013, as well as models to estimate vehicle operating costs (VOC) and, in turn, the calculation of road user costs (RUC) for the purposes of cost-benefit analysis (CBA).
The various methods used to estimate VOC and RUC are reviewed, including their technical bases as reported through various Austroads studies, recognising the need to provide models that possess the following attributes and that can be applied and updated in a clear and consistent manner to:
- Better accommodate changes in vehicle technology and a changing vehicle fleet, including under different loading conditions and regulations
- Be amenable for application across networks subject to uninterrupted and interrupted/stop-start conditions
- Be capable of application to general cost-benefit analysis studies at a network level and for major capital projects, including employing the results of traditional 4–5 stage transport models.
By addressing such issues and using a sufficiently well-defined vehicle fleet classification, and through regular updating of the unit values and models, this update should improve consistency in CBA and other related applications.
Updated parameter values are provided for the following vehicle road user effects (RUE) components:
- Direct road user effects (RUE) components - fuel, oil, tyres, repairs and maintenance, depreciation (through new vehicle prices)
- Travel time – vehicle occupants (passenger and freight) and freight per vehicle type
- Crash costs – average cost of crashes by injury severity across jurisdiction, based on human capital and willingness to pay approaches
- Vehicle operating cost (VOC) models – a review is provided of the state of rural (free/uninterrupted flow speeds) and urban (interrupted flow speeds) VOC models in Australia and updated values for VOC ($/km) and fuel consumption (litres/km). Appropriate models are also specified for uninterrupted and interrupted flow, together with coefficients
- Vehicle classifications appropriate to Australia – an overview is provided of developments in vehicle classifications in Australia, including a 20 vehicle classification used for application of parameter values. This was undertaken as it is broadly consistent with the vehicle classification in Austroads (2005a) and provides a sufficiently broad range of vehicle types from which practitioners can select the vehicles most appropriate to their local vehicle fleets. The vehicle classifications used in Australia, including the Austroads 12 bin classification outlined in Austroads (2013), are presented in Appendix C
- Updating of parameter values - guidance is provided to practitioners on the indexation of parameter values per RUE component until a new set of parameter values is released.