Research On The Minimum Distance Between Highway Tunnel Exit And Main Line Exit And Its Control Countermeasures

The development of the transportation industry is closely related to the country’s economic level and scientific and technological capabilities.Over the past few decades,the country’s economy has continued to grow,its scientific and technological capabilities have improved significantly,and the transportation industry has also made considerable progress.The mileage of the national expressway network continues to grow,and some areas with difficult terrain such as mountainous areas have also achieved expressways.In mountainous highways,tunnels are often used to overcome terrain difficulties,but this also increases the difficulty of driving for drivers.The exit section of the tunnel and the main line is an important part of the expressway,and it is also an area where accidents are relatively concentrated.The distance value directly affects the operating safety and service level of the expressway.Based on some factors in design,management,technology and terrain conditions,the distance between the tunnel exit and the main line exit is too small.These problems still exist on some expressways with difficult land use.As a result,traffic conflicts on this section of the road are serious and accidents occur frequently.In this paper,the study of the minimum distance between the exit of the highway tunnel and the exit of the main line is carried out by referring to relevant research results at home and abroad.This article studies the section from the exit of the highway tunnel to the exit of the main line.First: analyze the various elements of the distance between this section and define it.Second: study the traffic characteristics of this section and analyze the various influencing factors of the distance.Third: From the most unfavorable point of view,that is,the vehicle is driving in the innermost lane that requires the most number of lane changes and the most difficult to leave the main line of the expressway.Using the lane change theory,consider the behavior and psychological characteristics of the driver when driving on this section of the road.,Disassembled each step of the driver’s departure from the main line of the expressway,derived the minimum clear distance calculation model with the formula for calculating the distance at each step,and gave the minimum clear distance recommendations for different lanes and different design speeds through the model value.Fourth: Based on the theory of traffic conflict technology,through iterative clustering and other methods,it analyzes how the traffic conflict rate evaluates the severity of traffic congestion,studies the internal connection between the two,and creates an evaluation model.Fifth: The simulation system is used to simulate different clear distances,and the control variable method is used in the simulation,that is,the simulation is performed under different number of lanes and different design speeds.A total of 9 sets of simulations were carried out,and the recommended net distance values under various combinations of design speed and number of lanes were obtained.Sixth: Compare the recommended value given by the calculation model with the recommended value given by the simulation system,and determine the recommended minimum clearance for different design speeds and different lane numbers under general and extreme conditions.Finally,corresponding improvement measures are given for the small clear distance section.The research results of this paper provide reference and reference significance for the design of new highways in my country,and provide certain practical significance for the reconstruction and expansion of small clear distance sections of existing highways.