Drivers approaching an intersection when the traffic lights change to amber have to decide whether to stop or to continue through the intersection. A dilemma zone is a stretch of the approach to an intersection within which the decision as to whether to go or stop is not clear cut. At higher speeds some drivers may be caught in a position where they must choose to either brake sharply or stop or continue and risk entering the intersection during the red. This can have safety implications as there is the potential for conflicts with other road users. This paper suggests a probabilistic model for the analysis of the dilemma-zone problem at high-speed signalised intersections with speed assessment (SA) control strategy. Methods for the calculation of the probability of the maximum change and that of a driver being caught in a dilemma zone will be presented and demonstrated using numerical calculations based on different definitions of dilemma zones found in the literature. The effects of traffic demand and traffic control parameters such as the maximum green will be discussed. (A) Reprinted with permission from Elsevier. For the covering abstract see ITRD E134766.
Abstract