Keywords: critical gap gap acceptance uncontrolled intersection mixed traffic clearing behaviorThe gap acceptance study is an indispensable study in the determination of capacity and delay of the individual moment at uncontrolled intersection and critical gap is one of the chief parameter allied with this study. Most of the studies related to critical gap estimation have been carried out in developed countries where traffic is homogeneous and rules of priorities as well as lane disciplines are voluntarily followed. However, in India, priority rules are less honored which consequently create more clashes on intersections and modelling of such behavior becomes complex. Even though very limited studies have been reported in such case. This paper presents the study of gap acceptance behavior of drivers on an uncontrolled intersection. In order to examine the gap acceptance behavior of drivers, 4-legged uncontrolled intersection located in a semi-urban area of Ahmedabad in the state of Gujarat was selected. Video recording technique was adopted for collection and analysis of the data. Different existing methods are used to calculate the critical gap for through and right turning movements from the minor road. Gaps are analyzed for three different vehicle types. A comparison between different existing methods of critical gap determination is carried out and their critical analysis is presented. The result shows, except clearing behavior approach, all other methods are failing to represent the actual scenario of the critical gap under mixed traffic conditions as these all methods had been developed for homogeneous traffic conditions.

No abstract

 Abstract-Critical gap is the most important parameter associated with gap acceptance study especially in case of delay and capacity estimation. Many studies are reported on gap acceptance behavior of pedestrian but most of them confined to developed country where traffic is homogeneous and traffic rules are strictly followed. Uncontrolled intersections in case of developed countries control the traffic and pedestrian movements based on priorities but in India, no one follows the stop and yield signs, even the rules of zebra crossings. It creates more conflicts and increases delay to both. This paper systematically analyzes the behavior of pedestrian during the gap acceptation at two four legged TWSC intersection located at Ahmedabad in state of Gujarat, India. Data on gap acceptance behavior is obtained by video recording technique and analyzed the various parameters relate to crossing behavior of pedestrian. The critical gaps for pedestrians estimated by raff method and results shows that values of critical gap estimated are as low as 3.20 sec. which is smaller than reported in other studies. An Adaptive Neuro Fuzzy Inference System (ANFIS) has been established to estimate the possibilities of accepting a given gap or lag considering the combinations of different parameters which affects the crossing behaviors of pedestrians. Nine different combinations are considered. However, the age of the pedestrian is found to be most important variable in crossing behavior compared to other.