OVERTAKING BEHAVIOUR ON MULTILANE HIGHWAYS

Abstract

National Highways in India constitute about 2% of the total road length in the country and carry over 40% of total traffic. Realizing this fact, major initiatives for capacity enhancement of National Highways have been taken by the Government of India. The national highway network forming the Golden Quadrilateral and North-South and East-West Corridors is being upgraded to four/ six lane roads to facilitate uninterrupted flow of traffic. In addition, the highways connecting major ports and several other National Highways are being upgraded. Hence, it is expected that, with this massive improvement and capacity augmentation of these highways, there will be a considerable increase in the speed of traffic on our National Highways. In the present study the arrival pattern, lateral placement, speed distribution of different types of the vehicles, acceleration rates of the different vehicles during overtaking maneuver and overtaking time taken by the vehicles are investigated through field data collected on different sections of National Highways and State Highways of India and are used to develop a simulation model, to represent the traffic flow on a multi-lane road. The simulation program has been coded in Visual Basic language for processing on a high-speed digital computer. The model is capable of incorporation six categories of vehicles, viz., car/jeep, bus/truck, tractor, two-wheeler, three-wheeler and bicycle. The performance of the model has been validated on macro level by obtaining the headways on a multi lane road and comparing the same. Simulation runs are performed at different flow levels and for mixed traffic consisting of two types of vehicles including passenger cars and any one of the remaining five categories of vehicles.