Concept Evaluation of Intersection Decision Support (IDS) System Interfaces to Support Drivers' Gap Acceptance Decisions at Rural Stop-Controlled Intersections

Abstract Rural stop-controlled intersections pose a crash risk for drivers turning or crossing the intersection from the minor road. In particular, elderly drivers are at the highest risk of a collision in this situation. Errors made during gap detection, perception and acceptance are the main factors that influence crashes at this type of intersection. This study investigated young (20–40 years) and old (55–75 years) drivers’ gap acceptance performance in simulated day and night driving conditions in a Baseline condition (STOP sign only) and four intersection decision support (IDS) conditions. The four IDS conditions were initial infrastructure-based design concepts that provided varying levels of dynamic information about traffic conditions on the major road to crossing minor-road drivers. Signs that provided detailed gap information (i.e., time-to-arrival values, warning levels for gaps) as well as advisory information about unsafe conditions resulted in the best performance among old and young drivers in comparison to signs that did not provide specific gap-related information (i.e., detected vehicles approaching, but not size of gap or safety of gap). Comprehension, acceptance and usability ratings of the IDS signs were also highest for signs providing detailed gap and advisory information on the same sign. Recommendations for further design and development of the IDS system interface based on driver performance and acceptance of the technology is discussed.