Safety Audits of Existing Roads (SAER) provide an independent and expert review of a Road Controlling Authority's (RCAs) provision of a safe travel environment. A SAER provides feedback to a RCA with respect to the things the RCA does well and those areas that may require additional attention. To date SAER has been administered by Transfund New Zealand to assist RCAs in their service provision, however there is a need to devolve the process to RCAs and to develop SAER further thereby allow RCAs to monitor their own performance. To do so requires a shift from the essentially qualitative assessment based on expert opinion to a more quantitative assessment. Therefore, the methodology of SAER has been revised. The revisions focussed on the safety issues identified, the assessment of impact severity related to a particular issue, and the relationship between the safety issues identified and known accident causation. A literature search of infrastructure accident studies provided accident rate data for various items composing the road environment. This data, along with typical accident rates for different classes of road, helped define road types. The audit process focuses on deviations both positive and negative from the road type standards. The deviations and the exposure, i.e. the proportion of road affected by the deviation, are recorded. This provides an assessment of the relative risk for the road being audited as compared to a standard road of that type in that terrain. To allow comparisons to be made between RCAs, factors were developed for roading context. These factors are road type or intersection type, terrain, and traffic volume. (Author/publisher)
Samenvatting