Evaluation of Exclusive Stopping Space for Motorcycles at Signalized Intersections Under Mixed Traffic Conditions Using Simulation Model

Mixed traffic flow with high composition of motorcycles is a common situation in most of the Southeast Asian countries like India. Motorcycles possess several unique features such as narrow width, small size, high power-to-weight ratio and intuitive steering. All this may lead them to have more freedom in a traffic stream and also perform some characteristic behaviour patterns in mixed traffic flow. Moreover, mixed traffic is characterized by a mix up of vehicles having diverse static and dynamic properties. This type of traffic is characterized by lack of queue and lane discipline based on availability of space near intersections. At intersections, left, through and right turning vehicles seek to occupy the same physical space. In such situations, the through vehicles are susceptible to delays. Moreover, observation in the field indicates that motorcycles tend to accumulate near the stop line by weaving through gaps during the red phase to facilitate an earlier discharge during the initial period of the green due to its smaller size and high manoeuverability, which reduce other modes’ speed and therefore, they may cause congestion at that time. Also, this leads to excess delay for other vehicles while discharging from the intersection. Many mega cities in Southeast Asia are suffering from a high degree of congestion, which is mostly caused by motorcycles. It is important for these countries to develop appropriate management strategies for motorcycles. Understanding its moving behaviors and modeling them in a more realistic way may help. For this purpose, a microscopic traffic simulation model for signalized intersection developed specifically for mixed traffic was used. This model covers different vehicle types, and allows for some special behaviors, such as seepage to fronts of queues by motorcycles. The model was calibrated and tested with data from Chennai city, India, and its predictions were found to be in close agreement with the field data. This model was used to simulate traffic flow on Exclusive Stopping Space for Motorcycles (ESSM) near stop line. The benefits of ESSM were studied by varying the vehicular composition, traffic volume and ESSM lengths. The findings show that for certain composition, volume levels and length of ESSM, delay to vehicles decreases which shows that ESSM is beneficial for all types of vehicles at intersections.