Capacity Analysis of Uncontrolled Intersections with and Without Pedestrian Cross Flow in Mixed Traffic Conditions

Indian traffic differs significantly from that of developed countries in many aspects, mainly due to its highly mixed nature and weak lane discipline. Capacity of an uncontrolled intersection plays an important role in the overall performance of urban road networks. The non-compliance of the road users to the traffic rules at uncontrolled intersections makes the situation complex. Moreover, roadside frictions like pedestrians interfere with the traffic flow in most of the intersections in India. Gap acceptance method for capacity estimation has few drawbacks in the practical application under the condition of non-compliance behaviour of drivers including influence of pedestrian cross flow. Capacity estimation of intersection with significant pedestrian cross flow can be possible using the conflict method. This paper aims to study the capacity reduction in uncontrolled intersection having significant pedestrian cross flow. For this purpose, traffic video data were collected from two uncontrolled intersections in Kochi City, onewais an ideal site without significant pedestrian cross flow and the other a pedestrian site with significant pedestrian cross flow. The capacity of ideal and pedestrian intersections was estimated using the Highway Capacity Manual (HCM) method as well as conflict method and a comparison was made between them. HCM method gave lesser values of capacity compared to conflict method and also gave unreasonably higher reduction in capacity due to pedestrian cross flow. This proves that HCM methodology is not suitable when the pedestrian traffic is also considered in addition to vehicular traffic in mixed traffic conditions. It was found that the capacity of the pedestrian intersection is 24.8% lesser than the ideal intersection. This study will be helpful for the traffic engineers to suggest a suitable pedestrian facility to reduce the conflicts between vehicles and pedestrians at intersections.