| With the acceleration of urban transportation in China,the density of urban traffic road networks is increasing,and the traffic problems that arise at the same time become more prominent.The tunnel exit is an important facility for the expressway.The expressway main road exit is an important part of the expressway.The road section is also a relatively concentrated traffic accident rate.The distance will directly affect the expressway operation quality and driving safety.The rational design for the expressway of the distance from the tunnel exit to the main road exit is critical for the safety of the vehicle.However,there are still many problems in the planning,design and management of our country,which lead to the small distance between the exit of the expressway tunnel and the exit of the expressway main road,and the traffic conflict rate increases.This dissertation studies the minimum distance between the exit of the expressway tunnel and the exit of the main road by referring to the relevant research at home and abroad.This dissertation defines the composition of the interval of the expressway tunnel exit to the main road exit,elaborates the traffic characteristics of the research section and analyzes the influencing factors affecting the spacing of the section.Taking account of the Traffic safety,this paper analyzes and discusses the most unfavorable situation.That is,the vehicle that drives out of the main road is in the innermost lane when driving out of the tunnel,based on traffic flow theory,lane change theory,acceptable clearance theory,and secondary deceleration theory,fully consider the driver’s behavior characteristics and traffic.Factor,establish a calculation model for the exit of the expressway tunnel to the exit of the main road.According to the classification of expressway,the recommended value of the minimum distance between the exit of the expressway tunnel to the exit of the main road with different design speeds and different lane numbers is given.The traffic conflict rate is used as the evaluation index to establish the gray cluster safety of the expressway tunnel exit to the main road exit.Evaluation model.Taking the exit of Dushuhu Avenue Expressway Tunnel in Suzhou as an example,the VISSIM simulation software was used to simulate the microscopic traffic flow of the Dushuhu Avenue tunnel exit to the main exit of different distances,and record the conflict rate of different lengths.The safety evaluation model evaluates the safety of the exit distance from the tunnel exit to the main road exit of different lengths,verifies the rationality of the minimum spacing value given in this chapter,and evaluates the safety of the distance from Dushuhu Avenue tunnel exit to the main road exit in Suzhou.In view of the prevalence of small-distance expressway tunnel exit to the main road exit section,this paper starts from the actual situation,proposes safety guarantee measures for the small-distance expressway tunnel exit to the main road exit section road to reduce or avoid traffic conflicts.The dissertation analyzes the distance control of the expressway tunnel exit to the main road exit section from the microscopic aspect.The research conclusions have reference significance for the planning,design and reconstruction of the urban expressway in China,and the improvement of the existing expressway tunnel exit to the main road exit small-distance section. |
