Study On Design And Effectiveness Evaluation Of Traffic Signs In The Highway Special Tunnel Section

Abstract:The tunnel section is normal on the highway in mountain areas, and a lot of safety problems are following. According to statistics, the traffic accidents per hundred meters in the special tunnel section are two more than the common section. Therefore, the operation safety problems in the highway tunnel section, especially the special tunnel section, are particularly prominent.Design the targeted and effective traffic sign is one of the effective ways to solve safety problems of the sections.For this reason, design and effectiveness evaluation of traffic signs in the highway special section were studied by the theoretical analysis, the field research and so on.The main results of the study are as follows:(1) According to their own characteristics, the highway special tunnel section was divided into five types, the long tunnel section, the continuous series of tunnel section, the curved tunnel section, the sloping tunnel section and the bridge and tunnel linked section. The operation safety problems in the highway special tunnel section were determined. And the corresponding countermeasures were proposed.(2) On the basis of safety ergonomics principle, it was the cognitive theory that was used to read the design elements and principles of the traffic sign. For color, it’s unsuited to use the demitint, and the abstract concept expressed by the color needs to be considered. For shape, the identity is considered. For the graphic symbol and word, the amount of information is considered. For the size, the visibility is considered. The standardability conforms to the "template theory". The figurativeness conforms to the "feature theory". The simplicity conforms to the information transmission rate theory. The aesthetic conforms to the motivation theory.(3) A bidirectional and four lane highway in Zhuzhou,Hunan was selected as the support project, and four research sections were determined.It was the uncleared danger rate that was used to identify and analyse the danger of the sections.The typical safety problems were discovered from the seventeen collected sign facilities, such as the unreasonable prepositive distance, the overlap, too small space between the sign facilities, too few sign facilities and the lack of warning signs which are used to explain the road conditions.(4) The design of the traffic sign in the highway special tunnel section was studied. The normalized design procedure of the sign was proposed by the flow chart. On this basis, the calculation method of the set locations was proposed by the driver’s dynamic visual field and the minimum resolution of human eyes, and the reasonable values of the prepositive distance, the transverse position and the suspension height were determined.(5)On the basis of the three links of the traffic sign design, influence factors of the traffic sign effectiveness in the highway special tunnel section were analysed. The effectiveness multistage fuzzy comprehensive evaluation system of the traffic sign was established on this basis.The system was applied to the support project. The effectiveness levels of the the traffic signs in the research sections were calculated, and the factors preventing the signs from working were identified. Helpful references of the safety improvement during operation period were provided for the support project.(6)From the real situation of the support project,the two new warning signs in the bridge and tunnel linked section and curved tunnel section were designed.Their respective reasonable set locations on the scene of the support project were determined.