Highway Ramp Signal Control Technology Research

With economic development, the car of large and medium-sized cities increase steadily, traffic congestion is also becoming more and more serious. Give full play to the efficiency of the freeway is propitious to reduce traffic pressure of the roadway, and make the whole road net system to improved. To make the freeway maintain good running, in addition to the need for a reasonable allocation of road construction facilities(such as the number of roadway, entrances and exits pitch, the length of accelerate and slowdown speed roadway, etc), Scientific and effective management of traffic control is also very important.The methods of the freeway control including entrance ramp control, main line control and routeway control, and other content. Of these, the entrance ramp control is one of the most widely applied and most effective form of control. Entrance ramp control has several ways, each method has its application traffic conditions. which applied more were timing control, inductive control and gap control.This subject provides a coordinated control method of more than one entrance ramp based on the length of the queue. The method determines whether use coordinated control or not depends on the length of the queue up the entrance ramp whether too long. When the length of the queue is too long, it needs coordinated control, otherwise, only use single entrance ramp control. When perform single entrance ramp control, take the method combines with the smallest adjustment, demand-capacity control , inductive control and gap control. It carries out take different methods in different traffic condition.In order to verify the reasonableness of the algorithm, the subject developed a corresponding simulation system. Simulation System composed by ramp controllers, data transfer interface software and PTV traffic simulation software. The simulation results show that, this algorithm carries out avoid the traffic congestion in the condition of largest used the capacity of main line of freeway. It also avoid some vehicles queued for a long time in the entrance ramp. In addition, algorithm use the traffic flow and percentage of traffic share replace the speed as control parameters, saves a lot of vehicle detector, greatly reducing the quantifier of construction.This subject has importance significance to resolve the traffic congestion of cityfreeway and improve the road service levels.