The Method Of Vehicle Merging Guidance At On-ramp In Highway Base On Cooperative Vehicle Infrastructure System

With the rapid growth of economic,the ownership of private car increase quickly,congestion and accident rates on freeway is much worse.Especially,accidents and congestion rate is obviously higher at on-ramp area,which is several times more than the basic road.At present,vehicle import at the ramp area is usually passively controlled to achieve the maintenance of traffic efficiency of the main line due to the limitation of data collection and traffic control technology.Real-time data acquisition and vehicle guiding on ramp area has been achieved based on the Cooperative Vehicle Infrastructure System(CVIS),active control of traffic demand has been realized to improve traffic efficiency and reduce the rate of accidents.Freeway ramp area is lacking method of controlling vehicle merging at present.Considering the influence that vehicles merging on-ramp effect on freeway mainline traffic flow,and analyzing the characteristic that traffic capacity and driving security would decline on freeway ramp area,the control strategy about vehicle merging considering the adjustment of vehicle speed on the main line under CVIS and considering vehicle lane changing on the main line under CVIS were put forward in this paper.A simulation based on the VISSIM traffic simulation software and its COM interfaces is conducted to verify the model,a final evaluation has been given according to the simulation results.The work completed in this article as follows:(1)The method of vehicle import on ramp area based on CVIS is put forward after analyzing the vehicle import problem on freeway ramp area.The security and efficiency of vehicle travelling in merge area is analyzed,and an overview about traditional ramp control method is listed.Then,the theory and technologies about CVIS are introduced,the traffic data collection as well as traffic control technology under CVIS is especially analyzed.Finally,a framework about vehicle merging at on-ramp area based on CVIS is put forward.(2)The control strategy about vehicle merging considering the adjustment of vehicle speed on the main line under CVIS is proposed,and vehicle merging model at on-ramp area considering the adjustment of vehicle speed on the main line is established.The security and efficiency of vehicle travelling in merge area is analyzed,and a vehicle merging guide policy aimed at avoiding reducing passing capacity and reducing vehicle collision rates is put forward.Merging gap at on-ramp area is found out by searching target merging gap and adjusting vehicle speed on the main line.The control strategy about vehicle merging aiming at ensuring security and efficiency of vehicle travelling is proposed based on vehicle speed guidance.(3)The control strategy about vehicle merging considering vehicle lane changing on the main line under CVIS is proposed,and vehicle merging model at on-ramp area considering vehicle lane changing on the main line is established.A further research about vehicle merge control has been made,a lane change model of vehicle besides the main lane is proposed.Then,a method of providing merging gap is put forward through the lane changing of mainline vehicle.The control strategy about vehicle merging considering vehicle lane changing on the main line is proposed.(4)A simulation research about the control strategy of vehicle merging considering vehicle lane changing on the main line under CVIS is made.A simulation based on the VISSIM traffic simulation software and its COM interfaces and C++ programming is conducted.The security and efficiency of vehicle travelling in merge area on freeway is analyzed to test the vehicle merging control model.The simulation result shows that the method proposed in this article can effectively improve traffic efficiency and traffic safety at freeway on-ramp area.