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Journal of Advanced Transportation
Volume 2018, Article ID 1350679, 9 pages
Research Article

Group Gap Acceptance: A New Method to Analyze Driver Behavior and Estimate the Critical Gap at Multilane Roundabouts

Department of Civil Engineering, Qatar University, P.O. Box 2713, Doha, Qatar

Correspondence should be addressed to Khaled Shaaban; aq.ude.uq@nabaahsk

Received 18 December 2017; Accepted 1 April 2018; Published 9 May 2018

Academic Editor: Irena I. Otković

Copyright © 2018 Khaled Shaaban and Hassan Hamad. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The operations of multilane roundabouts, especially three-lane roundabouts, are unique and more complicated than any other type of roundabouts. This study aims to analyze driver behavior and estimate the critical gap at three-lane roundabouts. Video data were collected at two roundabouts. The analysis identified a pattern of group gap acceptance, where vehicles entering the roundabout from different lanes moved in groups during the same gap. In this case, the decision of vehicles entering from outside lanes greatly depended on the gap acceptance decision of vehicles in the inside lane. Analysis showed that the vast majority of the vehicles accept the gap in groups and the critical gap was estimated accordingly. The study provides a new explanation for the operation at multilane roundabouts. The use of this simple method is recommended when estimating critical gaps for multilane roundabouts.