Application of Gap Acceptance Concept to Investigate Crossing Behaviour of Pedestrians at Unsignalized Intersections

In this study, an attempt has been made to study the gap acceptance behaviour of pedestrians to establish safety margins while crossing at unsignalized intersections. To examine the gap acceptance behaviour of the pedestrians, road geometric and traffic data were collected from 42 unsignalized intersections of seven Indian cities. Equilibrium probability method and maximum likelihood method were adopted for the estimation of critical gap of pedestrians on the basis of different demographic factors. Comparison between these two methods shows that equilibrium probability method is more suitable for estimating pedestrian critical gap at unsignalized intersections in mixed traffic condition. Analysis shows that the average critical gap for a young pedestrian is (5.31s) less than that for a middle-aged (6.49s) or old pedestrian (6.09s), whereas regarding gender, the average critical gap for male is (5.7s) less than that for female (6.1s). It has been noted that with increase in critical gap, the crossing time increases logarithmically. Pedestrian safety margin model has been developed with the help of ridge regression technique. It was found that critical gap and crossing time had significant effect on the safety margin of the pedestrian. The model was validated with R-2 valueof 0.75 and the model output showed that 7% of pedestrians took high risk while crossing, as their safety margin was observed to be nearly zero.