Proposing new traffic operation index to improve interchange type selection procedure

Abstract

An appropriate interchange type selection would help tackle traffic problems and avoid a decreasing level of traffic service and safety. Design alternatives are usually generated according to an engineer's experience. However, some useful types may be neglected. The criteria for interchange type selection vary from one study to another, but the criterion that should be considered first is the traffic performance. In this paper, an algorithm is suggested to auto-generate design alternatives. A fuzzy-based method is also proposed to investigate traffic performance, as well as to compare and prioritise the interchange design alternatives. The method is applied to two real-world interchanges. The findings show that the traffic performance could be improved by choosing an appropriate placement for loops and directional ramps. Finally, the results imply that more money would be saved by using the proposed method.