Technical Analysis Of Continuous And Downhill Tunnel Exit And Interchange Traffic Safety Technology

Based on the research project of traffic safety improvement for the continuous long downhill tunnel of Fuyi Expressway,this paper analyzes and studies the traffic accident characteristics of the tunnel section after defining the continuous long downhill tunnel.On this basis,the traffic sign position of the continuous long downhill tunnel exit section and the minimum distance between the tunnel exit and the intercommunication section are studied.At the same time,the traffic safety measures of the continuous long downhill exit and intercommunication section are also studied.Mainly got the following conclusions:(1)In this paper,a tunnel with a length greater than 3 km and an average longitudinal slope greater than 1%is proposed as a continuous long downhill tunnel.(2)The tunnel section is a high-incidence section of death accidents.The accident rate and death rate are high on sunny days,followed by rainy days and cloudy days.The rear-end collision and impact fixture accidents are the main manifestations of traffic accidents.The impact of fixed objects is high,but the fatality rate is low,and the rear-end accident is high and the mortality rate is high.Traffic accidents occur during peak travel periods such as holidays.Traffic accidents during the daytime tunnels occur between 10:00 and 17:00,and nights occur at 21 to 23 o’clock.Night accident rates occur less often than during the day.(3)Through the modular design,an indoor simulation test platform was established.(4)Through the study of the indoor test of traffic signs,it is concluded that when the traffic sign is located in the tunnel,the reaction time is minimum and the traffic is at the top of the tunnel.The average response time is 2.56 seconds.The reaction time is the longest for the right lane and the sign is at the top of the left lane of the tunnel.The average reaction time is 3.18 seconds.When the traffic sign is outside the tunnel,the minimum response time is that the right traffic sign is on the right side of the road,and the average response time is 2.05 seconds.The longest reaction time is that the right driving sign is located on the left side of the road,and the average reaction time is 2.44 seconds.The traffic signs inside and outside the tunnel have the same reaction time.When the traffic sign and the lane are on the same side,the reaction time is shorter than the opposite side.The analysis suggests that the cause of this phenomenon is not only related to the driver’s gaze location,but also to traffic regulations and driver driving habits.The response time of traffic signs in the tunnel is greater than that outside the tunnel,with an average increase of 0.6 seconds.The traffic sign inside the tunnel should be placed at the top of the tunnel.The traffic sign outside the tunnel should be placed on the right side of the road.(5)Field experiments were carried out on the apparent adaptation time of the continuous long downhill tunnel exit.Tests have shown that the normal fluctuation range of the pupil diameter change rate in ordinary high-speed sections is ±5 percent.At the exit of the tunnel,the ratio of the diameter change of the pupil in the tunnel fluctuates more than outside the tunnel.After the tunnel is exited,the pupil diameter change ratio is restored in a short time and is stabilized.The tunnel adaptation time is mainly concentrated in 1-2.5 seconds.The average time of the tunnel exit is 1.782 seconds.(6)The minimum distance between the exit and the intercommunication of the continuous downhill tunnel at a speed of 80 km/h is obtained.When the traffic sign is inside the tunnel,the minimum spacing is 348 meters.When the sign is outside the tunnel,the minimum spacing is 442 meters.On this basis,the minimum distance between the exit and the intercommunication of the continuous long downhill tunnel is proposed.When the traffic sign is inside the tunnel,the minimum spacing is 400 meters.When the sign is outside the tunnel,the minimum spacing is 500 meters.(7)According to the characteristics of continuous long downhill tunnels,corresponding traffic safety measures are proposed for the continuous long downhill tunnel exit and intercommunication sections from the aspects of traffic safety technical measures and management measures.It mainly includes traffic signs,setting techniques for marking lines,control of vehicle speed,adaptation of the environment inside and outside the tunnel,collision avoidance,strengthening and regulation of vehicle violations.