Designing Reasonableness Research Of Guide-signs On Urban Roadway

Urban roadway guide sign is one of the most important and powerful traffic control facilities by which traffic engineers communicate with road users to make sure that their ideas of design are fully and correctly understood by the road users.A perfect design of guide sign can ensure the vital safety function and efficient traffic operations.Thus,it is become a significant component of modern green city.Unfortunately,the national standard has not been implemented everywhere effectively and correctly because of the different situations in different cities.Various ambiguous designs confused the road users and worsened traffic operations.In order to solve the problems,sorts of guide signs at home and abroad have been collected.And the design rationality for guide-sign were deeply analyzed from point of view on dynamic visual acuity,taking readability and understand ability as the basic principle.Firstly,the existing research literature on the subject of urban roadway guide signs and drivers visibility at home and abroad were reviewed.From point of view on dynamic visual acuity,this paper analyzed the driver visual cognition process to layout information of traffic signs.Then,the legend designs or actual layouts of guide signs used in major cities in China have been collected and analyzed through comparing with selection of layout guide information,specific layout patterns and text layout design.A experimental scheme of readability understand ability and En-Route motorists information demands was designed and carried out,which aimed at above various of legend designs and actual guide signs' forms in different cities.On this basis the new optimal designs were proposed.Furthermore,the models of set position or front distance between the guide signs and intersections stop line were discussed and calculated under the different speed at different categories for urban roadway.Finally,a evaluation model was established adopting Human Factors Engineering evaluation methods.Using the model the cognition degree evaluation to different information layout of guide signs was evaluated.The results show thatthe correct cognition degree of the new optimal designs are obviously superior to the existing forms,and it can also indicates the design rationality of new guide signs' schemes are obviously superior to the existing forms.