The influence of the rate of circulating flow and delay on a driver's behavior at roundabouts.

Abstract

At roundabouts, a driver's decision to accept or refuse a gap has safety implications. Many factors influence the decision, including roundabout geometry, gender, age, driving experience, vehicle type, and traffic flow circumstances. This study looks at the effect of circulating flow rate and delays on a driver's choice to accept or reject a gap. The required data included the accepted gap, rejected gap, circulating flow rates, and delay. More than 12,000 gap measurements were acquired using a video camera approach. A frame-by-frame method has been used to analyze the recorded videos to extract the data required for further analysis. These data were analyzed based on vehicle type and lane direction. The results demonstrate that delay and circulating flow rate have a significant impact on driver behavior. Higher circulating flow leads to higher delays; consequently, drivers accept a shorter gap. The critical gaps obtained for motorcycles, light vehicles, and heavy vehicles are 2.72 s, 3.25 s, and 4.5 s, respectively. Meanwhile, the observed critical gaps for the right and left lanes are 3.25 s and 2.82 s, respectively. The output of this study provides a vital base for understanding the impatience and aggressiveness of a driver's behavior at roundabout entry, which has a significant influence on roundabout performance and safety.