INVESTIGATION OF TRANSPORT FLOW DELAY AT UNSIGNALIZED INTERSECTIONS WITH LIMITED SPEED

Abstract

Introduction. Many studies have argued that traffic delays at unregulated intersections depend on the intensity of the main flow and the intensity of pedestrian flow. Purpose. It is proposed to investigate traffic flow delays using the VISSIM software environment at unsignalized intersections at different flow rates. Results. Areas of the street and road network for experimental research were selected in the central part of Lviv. Triangles of visibility distance are calculated, problem places where it is necessary to establish a road sign 3.29 “Limitation of the maximum speed of movement” are defined. An analysis of existing methods for determining traffic delays at unregulated intersections is carried out at the paper. The method of estimating the average speed of traffic flow and the method of simulation modeling of transport flows in order to build a theoretical model are presented. The analysis of the dependence of the change of transport delays, obtained based on measured actual data and the method of modelling traffic flows, is carried out. The visibility distance for each intersection is calculated taking into account the speed mode. Graphical dependences of the change of the average and maximum length of the queue of vehicles under different modes of traffic light regulation in the secondary direction are given. It is determined that the average flow speed varies from 17 km/h to 38 km/h when changing the maximum speed limit from 15 km/h to 40 km/h. It is established that the lowest average traffic delay at unregulated intersections is observed at a traffic flow speed of 30 km/h. Conclusions. The substantiation of the introduction of the recommended speed regime on sections of streets with limited speed is given which takes into account transport delay, queue length, geometric parameters of the street, the presence of public transport stops and pedestrian crossings, traffic intensity and composition. The proposed method of controlling secondary traffic flows at unsignalized intersections, allows to increase traffic safety when traveling in secondary vehicles.