Research On Quantization And Evaluation Of Traffic Sign Information At Road Networks Linking-up Section

The linking-up section is the only connecting road between the road networks,the important hub of traffic flow transformation,and the important node in the whole road network.The paper aims at the deficiency of domestic and foreign researches on the quantization and evaluation of traffic signs information at road networks linking-up section,reveals the inherent regularity of the visual cognition of traffic signs form the information theory,traffic engineering and cognitive psychology,establishs the quantitation and evaluation model of the traffic signs information at road networks linking-up section,and establishes a foundation for the complete traffic signs system at road networks linking-up section.Firstly,based on comparing and analyzing the differences between freeway network and urban road network,the networks linking-up section between urban road network and freeway network was selected as the research object.The networks linking-up section was defined after analyzing the road networks connection patterns.On this basis,selecting the linking-up section of Shangjie interchange in G70 as an example,traffic characteristics such as vehicle speed variation,traffic composition of road networks linking-up section which includes freeway section,ramp section,urban road section were studied in order to set the environmental basis of quantization and evaluation of traffic sign information at linking-up section.Secondly,considering the inter relationship between traffic signs information symbols and the influence of traffic sign character height,the discrete information,joint entropy and character-high parameter were introduced to study on the memoryless information quantity of traffic signs independent subset and the memory information quantity between related subsets.The information attention-degree was also introduced by considering the difference of driver's attention degree to different subsets of information among different sections,the traffic signs information calculation model and density model at linking-up section were eventually established.Then,the traffic signs' visual recognition experiments under different speeds of road networks linking-up section were designed by using E-Prime software to study the correlation between visual recognition time and the memoryless information quantity,the memory information quantity of traffic signs whether considering character height parameter and information attention-degree or not.The memory information quantity of traffic signs considering character-high parameter and information attention-degree were found by the research to reflect the impact of traffic sign information on the drivers,and threshold values of the traffic sign information quantity and the traffic sign information density were determined at different speed.Finally,based on comprehensive analysis of factors affecting traffic sign information system,the greater influential factors of driver's visual recognition of traffic signs information which include the quantity,continuity and accuracy of traffic sign information were selected and quantitatived.The evaluation model of traffic signs information system at linking-up section were established.The research has an important guiding and practical significance to the design and optimization of traffic sign information system at road networks linking-up section.