The use of accident data to assess the effectiveness of a primary safety (accident avoidance) feature can be problematic. This is because when a primary safety feature is fully effective, there is no accident and no data for comparison or analysis. Furthermore, most available accident databases are focused on accident outcome (secondary safety), and have insufficient data on the pre-crash phase and accident causation. A wide range of techniques are available but they all have strengths and weaknesses and none will provide an ideal solution for every safety feature. It is therefore also important to ensure that the most appropriate technique is used and that the strengths, weaknesses and any assumptions used are transparent. This report presents a methodology developed for the assessment of powered two-wheeler (PTW) safety systems. The implementation of this methodology is demonstrated by assessing the benefits of three advanced braking systems. The development of a desktop tool is also included. The output from the desktop tool includes casualty numbers by severity, the prevention value associated with the PTW casualties and PTW casualties as a proportion of all casualties. The annual data is presented alongside the three-year average. (Author/publisher)
Samenvatting