Emergency braking at intersections: A motion-base motorcycle simulator study.

Powered two-wheeler riders are frequently involved in crashes at intersections because an approaching car driver fails to give right of way. This simulator study aimed to investigate how riders perform an emergency braking maneuver in response to an oncoming car and, second, whether longitudinal motion cues provided by a motion platform influence riders' braking performance. Twelve riders approached a four-way intersection at the same time as an oncoming car. We manipulated the car's direction of travel, speed profile, and its indicator light. The results showed that the more dangerous the situation (safe, near-miss, impending-crash), the more likely riders were to initiate braking. Although riders braked in the majority of trials when the car crossed their path, they were often unsuccessful in avoiding a collision with the car. No statistically significant differences were found in riders' initiation of braking and braking style between the motion and no-motion simulator configurations.

Effects of in-car support on mental workload and driving performance of older drivers.

OBJECTIVE: This study examined the extent to which driving performance of 10 older (70-88 years old) and 30 younger participants (30-50 years old) improves as a result of support by a driver assistance system. BACKGROUND: Various studies have indicated that advanced driver assistance systems (ADAS) may provide tailored assistance for older drivers and thereby improve their safe mobility. METHOD: While drivers followed an urban route in a driving simulator, an ADAS provided them with prior knowledge on the next intersection. The system was evaluated in terms of effects on workload and safety performance. RESULTS: Messages informing drivers about the right-of-way regulation, obstructed view of an intersection, and safe gaps to join or cross traffic streams led to safer driving performance. A message regarding an unexpected one-way street led to fewer route errors. In general, effects were the same for all age groups. Workload was not reduced by the support system. CONCLUSION: The evaluated support system shows promising effects for all age groups. Longer evaluation periods are needed to determine long-term effects. APPLICATION: The messages provided by the evaluated system are currently not provided by existing ADAS such as advanced cruise control and navigation systems, but they could possibly be added to them in the future.

The development of a method to measure speed adaptation to traffic complexity: identifying novice, unsafe, and overconfident drivers.

To monitor novice driver performance in the first years of solo driving, a test aimed at assessing speed adaptation to the traffic situation was developed and evaluated. The Adaptation Test consisted of 18 traffic scenes presented in two (almost) identical photographs, which differed in one single detail, increasing the situation's complexity. As the pictures were presented randomly and participants could not return to previous pictures, participants were kept unaware of the complexity differences in the pictures. The difference in reported speed between the two pictures was used as an indication of drivers' inclination to adapt their speed to the complexity of the traffic situation. Results showed that novice drivers (n=434) performed worse on the Adaptation Test (i.e. less often reported a lower speed in the more complex situation) than experienced drivers (n=173). In addition, unsafe drivers and overconfident drivers, as identified in an on-road driving assessment, performed worse on the Adaptation Test. This indicates that the Adaptation Test is effective at measuring adaptation of driving speed to the complexity of the situation; and that incorrect self-assessment, and overestimating driving skills in particular, may have a negative effect on speed adaptation.