Driver's merging gap acceptance behaviour at roundabout

Abstract

Roundabout has been commonly used in urban and suburban areas for regulating traffic movements at an intersection through which conflicts are minimized. Its usage is deemed as having a reducing effect on accident as traffic merge, weave and diverge at small angles, and low speeds. At roundabout, circulating vehicles have priority of movements and all potential merging vehicles are to accept or reject the available gaps while waiting to merge. It is therefore, essential to study the merging gap acceptance at roundabout in order to characterize drivers' behaviour. Critical gap and follow-up headway are the key measures used for operational analysis and characterizing drivers' behaviour at roundabout. This paper presents an evaluation of Malaysian drivers' behaviour at roundabout through estimation of critical gap and follow-up headway. Raff's and Macroscopic probability approaches were used for the estimation of critical gap while follow-up headways were estimated from event time records. Findings from the study revealed that Malaysian drivers are aggressive as they tend to accept short merging gaps and follow-up headway, respectively.