Estimating hazards in traffic situations

Abstract

Hazards are attributes of road traffic. Safe driving requires perception of hazards and their combination into an overall evaluation of hazardousness of traffic situations. This process has been called hazard cognition. Results of previous studies could not show how drivers come to those cognitions. Because of the number of factors which contribute to these cognitions hazardousness can be seen as a multidimensional attribute of traffic situations. Drivers must recognize the dimensions of this attribute. To find out if drivers can do this, two experiments were conducted. In both experiments methods of multidimensional scaling were applied to pictorial representations of traffic situations. In Experiment I subjects comparing 16 situations with respect to hazardousness estimated more or less the magnitude of hazardousness. Results from indirect similarity ratings of 38 situations in Experiment II demonstrated a strong influence of driving experience. Less experienced drivers (75,000 km on average) stick more closely to details of situations and judge types of hazardousness, whereas more experienced drivers (150,000 km on average) judge hazardousness in a more holistic manner, obviously integrating different aspects of traffic situations. However, a common characteristic of all situations estimated as to be hazardous was a fairly high load of information on the driver. This certainly does not mean an equivalence of information load and hazardousness but results of these studies demonstrated the loading character of hazard control.