Functional Requirements for In-Vehicle Dilemma Zone Warning System at Signalized Intersections

Functional requirements and an operational algorithm to establish in-vehicle dilemma zone warning systems (DZWSs) at signalized intersections are provided as a part of the driver advisory and collision warning system in the automated vehicle and highway system. The DZWS project, one of Korea’s national intelligent transportation system projects in 2000, is developing an in-vehicle warning device to support drivers’ decision making on whether to stop or to proceed to clear the intersection before the onset of a yellow signal to avoid the high risk of a collision at signalized intersections. The dilemma zone concept, resulting from research and methodology pioneered in traffic engineering on drivers’ decisions, has been used to design the yellow warning interval. The operational and functional concepts of the DZWS are explored for appropriate approach speeds and deceleration rates at two signalized intersection sites. Findings from this research suggest that the algorithm should be implemented in developing and testing in-vehicle DZWS at two signalized intersection sites to improve driver compliance with stopping at the onset of yellow.