Capacity increasing of arterial streets with controlled motion

The problem of capacity increasing of arterial streets with controlled motion is investigated in this paper. For investigation, sections between intersections on the road network of Lviv city were chosen at their different length and roadway width with most saturated traffic. Methods of capacity increasing of arterial streets with controlled motion and factors that have impact on the capacity reduction are analyzed. Capacity of intersections at different volume-capacity ratios is determined. The distribution of average speed for sections between intersections of different length is built. It is established that on sections of medium length between signalized intersections and the high volume-capacity ratio, the speed of traffic flow does not reach maximum values. It is possible to increase the speed and the capacity of sections between intersections by increasing their length, sufficient for flow acceleration to the maximal constant speed and further braking before the intersection. To determinate the recommended speed of movement on arterial directions, road conditions are taken into account, which are formed with simultaneous impact of several factors: volume-capacity ratio of intersection in braking zone, volume-capacity ratio of intersection in acceleration zone, the number of lanes, the length of the section between intersections and the average speed of the traffic flow. It is determined that the average speed of traffic flow on short sections between intersections (the length less than 300 m) is 27 – 33 km/h, on sections of medium length – 35 – 38 km/h/ Such speed will allow to traffic flow reaching the line of constant movement in given road conditions. Conducted research allows taking into account road traffic conditions while justifying the calculating speed of traffic flow, in result of which capacity of arterial streets of controlled motion increases.