Two-wheeler vehicles (i.e., bicycles, mopeds, and motorcycles) are becoming increasingly popular in congested cities because of their small dimensions, low cost of use compared to cars, and their contribution to a healthy lifestyle. Even though the use of two-wheelers offers benefits, their low conspicuity, instability, and vulnerability of the users create safety risks. Due to their small size, two-wheelers tend to be overseen by other road users, especially at intersections. Furthermore, the stability of two-wheelers is easily affected by disturbances such as an uneven road surface. Moreover, the unprotected state of two-wheeler users contributes to a high risk of serious injuries once an accident happens. A better understanding of how crashes occur in the rider-vehicle-road system is needed. The research in this dissertation focuses on the cognitive and motor performance of two-wheeler users in safety-critical situations. Experiments were conducted among conventional cyclists, users of electric bicycles, and motorcycle users. An electric bicycle is a relatively new type of vehicle that has been adopted particularly by older people. This uptake creates an additional safety risk as older people are a vulnerable group in traffic because of their physical frailty. The first scope of this dissertation concerns the investigation of cyclists’ hazard anticipation performance and the examination of whether hazard anticipation performance can be enhanced with a short training intervention. The following two research questions are addressed: 1) Which situational and individual factors influence cyclists’ hazard anticipation performance in safety-critical situations at intersections? 2) How does a training intervention affect cyclists’ hazard anticipation performance and perceived risk? The second scope of this dissertation concerns the investigation of two-wheeler users’ riding performance and their self-assessments in critical intersection situations and in low-speed tasks. The following two research questions are addressed: 3) How are two-wheeler users’ characteristics at the strategic and tactical levels associated with braking performance in safety-critical intersection situations? 4) How does cycling performance in low-speed tasks differ between riding an electric bicycle and riding a conventional bicycle? (Author/publisher)
Abstract