This chapter briefly discusses some of the problems in assessing the impact of road transport informatics (RTI) systems on road traffic safety. 'Road traffic safety' needs an agreed definition, for example, the prevention and reduction of road accidents, or at least relative protection from exposure to hazards. Each prediction about systems, not yet introduced to the market, has to be based on various assumptions. Even if a system assessment is based on experimental studies, various considerations make it very difficult to predict the future, and show how speculative an assessment must be. All current development activities are guided by the expectations that: (1) driver information will be improved; (2) some forms of driver assistance and supervision will positively improve road traffic safety. Although these expectations are based on many human factors studies and much traffic safety research, it is still necessary to justify the potential safety impact of RTI systems being developed by: (1) reasonable assumptions; (2) carefully designed experiments; and (3) experience with comparable systems.
Samenvatting