OPERATIONAL EFFECTS OF ACCELERATION LANE ON MAIN TRAFFIC FLOW AT DISCONTINUITIES

Abstract

Recent studies have indicated that on-ramp flow is important in the formation of the stop-and-go traffic flow near the ramp. Several models have been developed to explain the complex phenomena associated with ramps which result in the hysteretic phase transitions. A good understanding of the mechanisms of congestion near on-ramps is very useful for the development of suitable control and highway design measures. To this end, in this paper traffic flow operations on a freeway with an on-ramp are investigated based on a newly developed second order macroscopic model. The proposed model allows to take into account the influences of the acceleration lane length on the flow dynamics of the main carriageway. The main aim of this paper is, therefore, to investigate analytically and numerically the effects of acceleration lane length on traffic flow operations. It is found that different acceleration lane lengths result in various congested traffic states.