Performance of junctions with a high motorcycle proportion

The present study dealt with the evaluation of the performance of signal-controlled junctions in urban areas, which exhibit high percentages of motorcycle traffic. In particular, the movement characteristics of motorcycles and the way they interact with passenger cars were investigated both qualitatively and quantitatively. Motorcycle movement affects the movement of the rest of the traffic and this impact on the operational performance of the junction approach was depicted. First, the way motorcycles move at a signal-controlled junction approach was described. To achieve this, another type of traffic lane was introduced: the ‘notional’ lanes, which were defined as corridors between stationary or moving traffic in the marked lanes. Next the movement of passenger cars and motorcycles was represented through vehicle headways and passenger car units. The movement of passenger cars at an approach was analysed and the way this was affected by that of motorcycles was identified. Finally, the performance of the approach was estimated through the start lag and saturation flow values, emphasising the impact of the movement of motorcycles at the junction.