This paper provides an operational algorithm to establish system functional concepts and requirements for the development of in-vehicle dilemma zone warning system (DZWS) at signalized intersections as a part of the Driver Advisory and Collision Warning System (DACAS) in the Automated Vehicle and Highway System (AVHS). The DZWS project, one of the Korea national Intelligent Transportation Systems (ITS) projects in 2000 develops the in-vehicle warning device to support drivers' decision making on whether to stop or to proceed to clear the intersection prior to the onset of yellow signal for avoiding the high risk of collision at signalized intersections. The dilemma zone concept referring to the research and methodology pioneered in traffic engineering related to the drivers' decisions has been utilized to design the yellow warning interval. This paper explores the concept of dilemma zone and the functional requirements relative to appropriate approach speeds and deceleration rates through collected data from two sites of signalized intersections and likelihood of driver selection for compliance with yellow interval timing. Findings from this research suggest that the operating algorithm for functional requirements would be implemented in developing and testing in-vehicle dilemma zone warning system based on drivers' behavioral data collected from two sites of signalized intersections with the goal of higher driver compliance towards stopping at the onset of yellow.
Abstract