Delay Time Estimation Of Individual Vehicles At Signalized Intersection Using GPS Data

The delay time of vehicles at signalized intersections is an important index to evaluate the service level and efficiency of the signalized intersections.Due to the limitation of technical conditions and testing methods,the existing methods of vehicle delay estimation are mostly for the average delay time of all vehicles in a certain period of time(i.e.the average vehicle delay).However,the average vehicle delay can not reflect the volatility of individual vehicle delay time.For the path optimization and navigation,only estimate the delay time of the target vehicle,and based on this to carry out path optimization and navigation is more targeted and reasonable.Therefore,it is of great practical significance to study the delay time of individual vehicles.Aiming at the above problem,this paper took the vehicles stopped in front of the intersection stop line as the research objects,combined with the characteristics of GPS data,through estimation the intersection signal timing parameters and the queue position of the vehicle in front of the signalized intersection stop line,and then established a new method to estimate the delay time of individual vehicles at signalized intersection using GPS Data.The main research contents include:(1)Signal timing estimation method based on GPS data.The existing method of signal timing estimation is based on the assumption that the vehicle is uniform arrived,and it can not respond the changes of the signal timing parameters in time.Aiming at the above problems,this paper used the intersection GPS data sequence,combined with the characteristics of signalized intersection,and then proposed a new method of signal timing estimation using GPS Data.The simulation test and field test are carried out under different traffic flows.The test results shows that the proposed signal timing estimation method is suitable for different traffic flows and the estimation effect is obviously better than the effect of the existing method.(2)Vehicle queue position estimation method.Considering the space headway of the queuing vehicles before the stop line are random and uncertain,this paper embarks from the reality,carried out a field survey of vehicle space headway,and then obtained the general characteristics of the space headway of the queuing vehicles though the analysis of the field survey data of the space headway.On this basis,the vehicle queue position estimation model was established based on the distance between the vehicle and the stop line.The model was tested at the flat peak and peak periods,and the results show the validity and applicability of the model.(3)Intersection delay time estimation method of individual vehicles.Based on the analysis of the headway field survey data of queuing vehicles,this paper obtained the general characteristics of the headway of queuing vehicles.The free flow speed of the vehicle through the intersection was defined.On this basis,combined with the research results of the signal timing estimation and vehicle queue position estimation,intersection delay time estimation model of individual vehicles was established.The model was tested at the flat peak and peak periods,and the results show the validity and applicability of the model.The above results show that the proposed intersection delay time estimation method of individual vehicles based on GPS data has a high estimation accuracy,and it can provide support for vehicle real-time scheduling,path optimization and navigation.