Study On Traffic Signal Warrants Of Intersections Based On Driving Mental Workload

The warrants of traffic signal at road intersections plays a very important role in improving traffic operation efficiency and ensuring traffic safety.My country’s current standard "Specifications for the Installation and Installation of Road Traffic signals"（GB14886-2016）is the main basis for the warrants and installation of intersection traffic signals.The comprehensive conditions of safety,pedestrians and bikes are vaguely specified,lacking theoretical basis and quantitative standards,and the role of guiding practice is not strong.It is necessary to find deeper theoretical support to supplement and improve.Based on task analysis of intersection driving scenarios（TAIDS）,this paper analyzes and compares the driving tasks of drivers at non-signalized intersections and signalized intersections from the dimension of fusion efficiency and safety driving mental workload,and determines the comprehensive method of warrants traffic signals at intersections.condition.First,the process of vehicles passing through unsignaled intersections and signalized intersections is divided into five stages and three stages,respectively.By qualitatively comparing the driving tasks of each stage,it is found that the driving tasks of the two types of intersections in the stage of "entering the intersection" There are obvious differences,and preliminarily screened motor vehicles,bikes,pedestrians,etc.as the main influencing factors of driving mental workload.Through the analysis of the drivers’ physiological measurement indicators,the root mean square of continuous heart rate difference reflecting heart rate variability（HRV-RMSSD）or the low frequency energy value in the frequency domain of heart rate variability（HRV-LF）were selected as the measurement indicators to characterize the psychological load of driving.Secondly,a natural driving test was used to collect the eye movement and RMSSD data of drivers in the process of selecting an intersection,and through analysis,it was determined that motor vehicles,bikes and pedestrians were the main dynamic factors affecting driving mental workload at the intersection.By analyzing the RMSSD index of drivers during peak and off-peak periods,it is concluded that the psychological load of driving increases monotonically with the traffic volume.Thirdly,based on the simulated driving test,the influence of three single factors of motor vehicles,bikes and pedestrians on the psychological load of driving in the two-way two-lane intersection is studied.The SCANER software is used to build a two-way two-lane intersection simulation scene to study the impact of motor vehicles,bikes and pedestrians on the psychological load of driving with different traffic levels.The method finds out the single-factor flow threshold condition for the intersection to set the traffic signal.Finally,based on the simulated driving test,the influence of mixed factors of motor vehicles,bikes and pedestrians on the driving mental workload in the two-way two-lane intersection is studied.The SCANER software is used to build a two-way two-lane intersection simulation scene to study the influence of motor vehicles,bikes and pedestrians with different flow levels on the driving mental workload.The multi-dimensional interpolation method finds out the multi-factor combined flow threshold condition for traffic signals to be set at the intersection.