Research On Optimization Of Expressway Guide Sign System Under The Condition Of Multi-factor Coupling

The guide signage system is an important part of the expressway infrastructure.In recent years,with the increasing improvement of the national expressway network,the density of the expressway network has been significantly increased,in view of which the country has made nationwide structural adjustment to the signage system.Along with the economic development,vehicle ownership is growing rapidly,and the service demand for expressway wayfinding signs from local vehicles and cross-regional long-distance vehicles is getting more and more refined.As a result,the existing wayfinding signage system is facing new challenges in terms of multiple factors and people's increasing service demands.Taking multi-factor coupling as the condition,taking road users as the service object,and improving the service quality of the wayfinding sign system as the goal,the optimization study of the expressway wayfinding sign system is conducted.Firstly,the current situation of wayfinding signs on the sample expressways is actually investigated,the problems of the wayfinding sign system are analyzed,the wayfinding sign system is redefined by type,the influencing factors of the wayfinding signs are determined and the coupling factors are defined,and the principle analysis and logical construction of the multifactor coupling effect are carried out.On this basis,a single wayfinding sign layout was designed and a questionnaire survey on the sign recognition effect was conducted to obtain different types of sign layout elements arrangement,information selection principles and optimization schemes;based on the eye-movement visual recognition characteristics,dynamic and static eye-movement visual recognition experiments on the combination form and layout form of wayfinding signs were conducted to explore the coupling effect of combination factors and the coupling effect of spatial density and supporting structure elements of the guidance sign system,respectively.The results show that the sign combination complexity,the spatial density and the support structure elements of the sign system The results show that the complexity of the sign combination,the threshold value of the combination information and the number of information distribution layout have a greater impact on the information conveyed by drivers,and the spatial layout density of the support structure of the guide sign has a greater impact on the driver's visual recognition load,and the sign layout is optimized to match the sign combination and layout form as the basic optimization scheme of the wayfinding sign system.On the basis of the above study,a driving simulation test program was designed,three test scenarios with different number of exits were built,and exit spacing and sign design scheme were considered as the coupling conditions,taking into account the "Visual +Cognitive + Operational + Effect" visual characteristics,psychophysiological influences and driving behaviors formed by drivers during the driving process.The evaluation indexes were selected for refined impact analysis and repeated measurement ANOVA,and it was found that there was no difference in the impact of exit ramp spacing,sign design and factor interaction on the number of brakes,number of gaze,sweeping time and number of times,and there was significant difference in the impact of eight evaluation indexes such as average speed,acceleration and braking effectiveness,which can be used as key evaluation indexes to verify the effectiveness and practicality of the optimization of the signage system.The effectiveness and practicality of the optimization scheme of the guide signage system.The entropy weighting method was used to determine the weights of the eight key indicators,and the TOPSIS method was used for comprehensive evaluation and analysis.The comparison study was conducted on several dense exit scenarios,and it was found that the combination of "speed limit by lane and vehicle type","next exit + location distance ","exit +straight ahead" multi-level advance notice and "multiple exit preview + straight ahead preview+ exit preview + exit signage" were the optimized solution for the guide signage system,and the most effective effect of wayfinding.The more the number of exit ramps and the closer the spacing between consecutive dense exits,the greater the interference to the driver's operation behavior,if the increase to two consecutive dense exits using a long spacing of 5km "optimization group" plan is optimal;if the increase to three consecutive dense exits,the exit location is closer to the destination,in order to ensure that drivers safely and efficiently drive away from the main line,using a short spacing of 2km "optimization group" plan is optimal.