The Conversion Method Research On Standard Pedestrian Equivalent Factors At The Signalized Crosswalks

With the spread and penetration of the concept of fine traffic management,pedestrian traffic has entered the stage of fine research.Different types of pedestrians have different crossing speeds and space occupancy due to internal or external reasons such as age,gender,and environment.Therefore,the crossing pedestrian flow should be a heterogeneous flow.In order to facilitate the exploration of the impact of various types of pedestrians on road capacity,a tool similar to PCE(Passenger Car Equivalents)needs to be found to convert mixed pedestrian flows into standard pedestrian flows for subsequent discussion and analysis.However,at present,there is a virtual void of research on SPE(Standard Pedestrian Equivalents)factor at signalized intersections in China.Based on the abundant measured data,this paper systematically analyzes the characteristics of pedestrian crossing at signalized intersection,and studies the method of SPE factor at signalized intersection.At first,it is very important to analyze the characteristics of pedestrian traffic at signalized crosswalks.The demand spatial characteristics of pedestrians,such as the maximum shoulder width and chest thickness,are obtained by reviewing relevant literature and reports.By investigating the pedestrian crossings of three crosswalks in the intersections between Nanhu road and Jinzi street,the intersections between Nanhu road and Qinglong road and the intersection between Huilong road and Shuanglong road in Chongqing,the data of pedestrian crossing speed was obtained by manually extracting data after video recording and the correlation analysis is carried out.According to the statistics of pedestrian arrival,it revealed that the pedestrian arrival patterns basically obeyed the negative binomial distribution.In addition,a model was developed to calculate pedestrian crossing delays based on pedestrian arrival patterns,which yielded 24.949 s for minors,24.586 s for young and middle-aged adults and25.397 s for elderly.On the basis of the study of the characteristics of pedestrian traffic at signalized crosswalks and with reference to the research method of PCE,the similarities and differences between pedestrian walking and vehicle operation are analyzed,and the principle of standard pedestrian selection,pedestrian classification principle and the validation of the rationality of pedestrian classification are established.Pedestrians were then divided into minors,young and middle-aged and elderly.Among them,young and middle-aged people were set as standard pedestrians.Immediately afterwards,three models were constructed for the projected area-based SPE factor method considering the static space of pedestrians,the projected area-based SPE factor method considering the dynamic space of pedestrians,and the delay-based SPE factor method.This model obtains three SPE values.Besides,this paper also uses Vissim simulations to explore the impact of different proportions of other types of pedestrians mixed into standard pedestrian flow on the value of SPE at the same LOS(Level of Service).The results show that at the same LOS,the proportion of the standard pedestrian flow mixed with other types of pedestrian has no significant effect on the values of SPE factor.Then,by comparing the error between the measured density and the conversion density,the conversion density,the measured pedestrian walking speed and the measured flow are selected to fit flow-density-speed relationship models to construct the three parameter relationship of the pedestrian flow.The Bell model was used to estimate the traffic capacity of the the signalized crosswalk,and the theoretical traffic capacity of the signalized crosswalk is 2390 p/h.Moreover,the validity of the SPE factor model for signalized crossings is verified based on the results of the theoretical capacity of the signalized crossings in combination with the values of SPE.Finally,the SPE is applied to the design of pedestrian crossing facilities,which proves that the SPE has practical significance.The research in this paper provides a theoretical reference for the further improvement of the research on the SPE factor model of crosswalks at signalized intersections.Furthermore,the application of this method can provide a more reasonable data source for signal timing and width design of crosswalk.