Relationship between delay, accepted gap and circulating flow at roundabout

Abstract

Capacity and delay are critical parameters to evaluate roundabout performance. This paper is attempted to investigate the influence of circulating traffic flow and gap acceptance on roundabout delay. All the data related to the analysis were gathered at a three-leg roundabout located at Kulai in Johor using video camera technique. The data were analyzed using a regression analysis technique:simple regression and multi-linear regression. The simple regression results show there is an exponential relationship between the delay and circulating flow and a power relationship between the accepted gap and delay as well as between accepted gap and circulating flow. The result of the multi regression between the delay, circulating flow and accepted gap gives high R-value. Despite the high R-value, the p-value of the circulating flow and accepted gap were found higher than 0.05 at 95% confident level; due to the high correlation between circulating gap and the accepted gap. This result can be used as a basis in developing a delay model for the roundabout in Malaysia, taking into account the influence of the drivers' behavior.