Research On The Redundant Setting Method And Effect Evaluation Of Side Guide Signs On Urban Main Roads

As an important infrastructure in the urban road system,directional signs mainly convey road information to road participants through symbols and text.However,directional signs belong to road ancillary facilities and have not received the attention and attention they deserve as the main project.With the popularization of intelligent portable devices and the increase in per capita motor vehicle ownership,drivers are more susceptible to interference from different factors in urban road environments,thereby missing the opportunity to recognize guide signs.The commonly used single setting method of guide signs cannot ensure the effective transmission of road information.Therefore,redundant setting methods need to be adopted to improve the fault tolerance of urban road sign systems,Reduce the risk of traffic accidents caused by serious traffic violations such as emergency lane changes,lane parking,and reversing due to drivers not obtaining target road information in a timely manner.This article focuses on the effectiveness of guide signs from the perspective of urban road managers and travelers,dividing the failure forms of guide signs into passive failure and active failure.It also studies the redundant setting methods of guide signs for different failure forms,providing scientific suggestions for formulating redundant setting standards of guide signs,and improving driver driving safety and efficiency.Firstly,based on the analysis of the passive failure scenario of large vehicle blocking in the outer lane,combined with the knowledge of queuing theory,traffic flow theory and probability theory,the passive failure distance and probability calculation model of roadside guide signs in the congested flow state were constructed,and the driver’s lane change probability under the redundant setting was further deduced.The redundant setting conditions of guide signs and the driver’s recognition results were converted into probability problems,A calculation method for the redundant setting spacing of directional signs under passive failure is provided,and the redundant setting frequency is determined based on the relationship between the driver’s remaining visual recognition time and the required visual recognition time of directional signs.A method for setting roadside directional sign redundancy for passive failure is proposed.Secondly,aiming at the driver distraction active failure scenario,the amount of guide sign information in different layout forms in the existing specifications was quantified through the information entropy model,the visual recognition time of guide signs with different amount of information was collected through the Eprime experiment,the correlation between the amount of guide sign information and the visual recognition time was analyzed,and the redundancy setting conditions considering the maximum pre visual distraction time were analyzed based on the pre visual and post visual distraction stages,The calculation process for the redundant setting spacing of roadside guidance signs under active failure was derived,providing reference spacing values for traffic management departments to adopt redundant setting of roadside guidance signs.In response to the difficulty in quantifying the occurrence time and duration of distraction behavior,the cumulative value of redundant setting spacing is used as a criterion for determining the number of redundant settings,and a method for setting redundant roadside guidance signs for active failure is proposed.Finally,combining the two redundant setting methods of roadside guidance signs from different perspectives mentioned above,VISSIM simulation and simulation driving effect verification experiments are designed to collect traffic flow data and driver eye movement data before and after the redundancy setting,and compare and analyze the effectiveness of the redundancy setting method.Based on experimental data collection,two sets of evaluation index systems for redundant setting of urban main road signage,namely the manager and traveler,were constructed.The CRTIC-FCE evaluation method was used to comprehensively evaluate the redundancy setting method.The effectiveness of the two types of roadside signage redundancy setting methods in this paper was verified from both experimental verification and theoretical analysis.