The results of previous work have shown that roads with higher geometric standards are safer. In fact the freeways (or motorways) are the safest form of road, being four times as safe as other roads. In Australia, where population is sparse except in the metropolitan cities, travel demand and economics do not permit all roads to be built to the highest standards. A significant proportion of Australian roads, especially in the country areas, have been built to lower standards. Improving design standards will undoubtedly improve safety on roads. The design standards refer to strategic decisions concerning the geometric standards to which the road is built. Such decisions may be made efficiently and rationally if the decision makers are aware of the effect of improving standards on reducing accident risk. Crash data and road data for the state of Queensland have been obtained from Queensland Transport and Main Roads respectively. These have been linked through the unique crash ID. Accidents have been classified by design features and qualitative and quantitative models have been developed that relate design features of roads to accident risk. These can be used to determine optimal design standards and efficient allocation of resources on constructing and maintaining roads from safety considerations. Specifically, the study examines the benefits of increasing lane widths, providing passing or overtaking lanes, providing shoulders, and increasing sight distance, on reducing road accidents. It also enables the estimation of benefits of incremental improvement in design standards by determining the accident risk reduction potential. The specific outcomes from this study include the estimation of specific contribution of improvements in the geometric design standards of roads to the reduction of accident risk. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E205861.
Samenvatting