Journals Proceedings

Abstract

The assessment and performance of signalised intersections often require the determination of capacity of approach lane or lane group, the intersection clearing speed of queued vehicle during queue discharge. The fundamental element of a signalised intersection is the periodic stopping and starting of the traffic stream. When a signal turns green from red, first of the stopped vehicles (1st vehicle of the queue) starts to move and cross the intersection. Then, the second vehicle in the queue starts to move and so on. The evaluation of capacity at signalized intersection is an important component in the planning, design, operation, and management of transportation system. Presently, the methodologies available for the estimation of capacity of signalised intersections are based on the concept of saturation flow (s). The study describes the headway, and speed characteristics of vehicles during queue discharge after green onset under mixed traffic condition. For the present work data were collected at different signalized intersections in the city of Bhubaneswar, India under highly mixed traffic conditions. It has been found that the queue discharge headways shows an unmistakable pattern of gradual compression as queuing vehicles are discharged in succession. However, contrary to the traditional concept of saturation flow, the discharge rates do not become stable after the fourth queuing vehicle enters the intersection. The average discharge headways become stable from position 6th (sixth) under mixed traffic conditions. The intersection clearing speed of queued vehicles at different queue position was also determined and the speed is in the increasing order. The average time required by vehicles to clear the intersection is also assed and the time decreases as the queue position increases.