Research Of Roundabout Control Model Based On Method Making Stop Line Move Forward

Roundabout with no signal control is adapted well to low saturability of trafficflow. Along with the urbanization process accelerating, road traffic demand is growing.Roundabout with signal control become more and more common, whileroundabout with no signal control become more and more congested. The vehicle driveinto roundabout slowly and influence each other. Because the process is long timeconsuming and the vehicle has lower speed,the influence get more obviously. So, forsafety, efficiency and reducing the delay, a new method of signal control is soimportant to roundabout control mode theories.This paper analyzed conflict characteristics and running characteristics of trafficflow of roundabout first. Then expounded the way of only one phase for an entrance,control principle and control mode of secondary signal control mode of left turningin detail. The VISSIM was applied to simulate the adaptability.A method making stop line move forward was developed. A distance model ofmaking stop line move forward was established. Taking cross roundabout for anexample, the design method of signal phase was researched. The phase overlap ofthrough running and left turning were developed based on the same traffic flow of leftturning and adjacent through running (anti-clockwise direction). The phase overlapmodel was established for safety and capacity, which parameters were phase overlaptime, interval time of the green light. Cycle time model based on Webster fit for themethod making stop line move forward was established when traffic flow of roundaboutwere saturation and unsaturation.The VISSIM was adapted to simulate the different radius, different left turn ratioand different saturability under the same condition. It analyzed the application conditionof the method making stop line move forward. Then the VISSIM was adapted tosimulate comparative analysis of the method making stop line move forward andexisting intersection control scheme. Taking roundabout of panxi road of Chongqing foran example, the simulation demonstrated the method making stop line move forwardwas available.