Analyzing driver's response to yellow indication subjected to dilemma incursion under mixed traffic condition

Under mixed traffic conditions prevailing on Indian roads, drivers show complex response when faced with yellow signal because lane assignment gets dynamic in nature. The present study analyzes the effect of surrounding vehicles on response of the drivers while facing dilemma at intersections. Although dilemma zone definitions hold true in case of homogeneous traffic mix, a statistical analysis is performed to check the consistency across the definitions under mixed traffic condition. Present study shows a significant difference in percentage of red light running in comparison to homogeneous traffic as reported by various studies. For carrying out the research, study locations are chosen in such a way to reflect diversity in road geometry, traffic composition and signal characteristics. The results deduced in this study indicate a strong correlation between the driver's decision making choice and the effect of presence of surrounding vehicle at the onset of yellow signal. The effect of critical time analysis has been found out to be one of the parameters other than critical distance in categorizing driver's aggressiveness while facing the yellow signal. In the process of identifying the statistical significance of dilemma zone definitions, it has been found that under heterogeneous traffic condition, drivers behave differently as compared to homogenous traffic when it comes to dilemma zone. It is observed that the percentage of vehicles crossing the intersection when faced with dilemma by violating the red light is 11.6% according to dilemma zone definition I whereas the definition II has yielded about 10.8% violation covering different vehicle types. The above violation figures derived based on the above definition is somewhat higher as compared to homogeneous traffic condition which is observed to be of the order of 5%–6%.