Scientific paper ID 1600 : 2018/3

The most common intersection is the four-way one (also called a crossroad), which differs in terms of the number, width and specialization of lanes, the magnitude of traffic flow in different directions, traffic conditions and other geometric features. To define the indications of traffic lights, an intersection signalling model has been developed using Excel add-ins providing input parameters through two dialog menus: for the amount of traffic in three typical time periods or only for particular counting and crossroad geometric feature. To obtain the type of phases, which are d in the cycle, the ”Method of sum of critical ratios for signal cycle” algorithm has been applied. It takes into account the crossroad geometry, magnitude of transport flows in directions and number of lanes, the use of throughput and amount of left-turning flows. Depending on the phases examined and the critical points involved in the obtained ”Matrix of intermediate times”, the sequence of phases is determined providing the smallest chance of an accident in regard to the intersection geometric features. As a The table obtained as a result shows the type of phases in the cycle, their arrangement, the average waiting time of a vehicle using the formula of Webster and overall assessment through the crossroad ”Service Level”. The developed modeling gives a possibility to evaluate the existing crossroad signaling and make comparison between it and the model obtained.