The Study On Color Influences Of Chevrons At The Curve Of Northern Highway Based On The Drivers’ Visual Characteristic

In snow and ice environment,road adhesion coefficient decreases so driver’s control of vehicles is less sensitive.As a result,there are more traffic accidents compared with common environment.And at the road curve,where the shape of the line changes,driver’s sight is limited,and the situation can be worse in snow and ice environment.Therefore,according to traffic characteristics of curves with ice and snow and driver’s visual characteristics,it will make great sense for improvement of the traffic safety condition at road curves in snow and ice environment to analyze effectiveness of traffic signs setting in this environment and make proposals on traffic signs selection suitable for different road conditions.With analysis on the travel characteristics at curves in snow and ice environment,a maximum speed limit calculation model based on object brightness is built and main factors impacting driving safety at curves are illustrated in this paper.Based on visual psychological theory traits,analysis on driver’s physical and psychological characteristics in snow and ice environment and common environment is carried out.And by questionnaire,this paper studies on the effects traffic sign’s color have on driver’s visual and psychology and gets results about driver’s subjective feelings to different colors of traffic signs and corresponding behavior reaction.This paper analyzes the fixation point,focus area and visual preference of drivers and researches features factors drivers choose to gaze at firstly in visual environment.Combined with the cognitive process and working principles of chevron alignment sign,a two-factor experiment is adopted with psychological experiment design methods.In order to study the influences road environment and traffic signs setting have on drivers and traffic flow speed at curves,this paper makes design on position setting of chevron alignment sign and carries out actual vehicles experiment in both common environment and icy environment with experiment equipment like SMI iView HED eye tracker and NC200 traffic analyzer.And by doing this,this paper observes distribution of driver’s fixation characteristics and traffic flow speed at curves under the influence of two different road environments and four different traffic sign design schemes.The researches result shows that ice and snow environment can not only influence the control of vehicles and braking characteristics but also have great impact on driver’s physiology and psychology,and that single dull driving environment and reflection of snow can result in visual and psychological fatigue.While setting suitable chevron alignment signs at curves in common and icy environment will help to improve the driver’s visual environment at curves and reduce the speed into curves so as to ensure traffic safety.Different setting of chevron alignment sign in different environment results in differences about driver’s fixation frequency,fixation time,pupil area and blinking characteristics.Through the two-factor analysis of road environment and sign setting,it is found that changes of road environment and sign setting both significantly influence vehicle speed while interaction between them doesn’t have much impact.According to difference of traffic flow speed and the effects before and after the signs setting,different effects of chevron alignment sign setting in different environment can be seen.In common environment,obviously green and blue signs are better than red ones;while in snow and ice environment,on the contrary,red signs are better than green and blue ones.