Motorcycle speeds at urban intersections

Abstract

Five urban, uncontrolled T-intersections known to be motorcycle crash ‘black spots’ were monitored using instrumentation and a roadside observer. Two sets of twelve-hour observations were collected for each site (N is approximately 100,000). Instrumentation recorded the ‘events’ of vehicles passing to measure, speed, direction, lane position, vehicle type (broadly characterised) and headway. Observers further recorded times of bicycle events, type of motorcycle (scooters or motorcycles), the behaviour of motorcycles and the use of ‘high visibility’ gear. Results establish that motorcycles travel around 10 per cent faster than the other traffic (car mean speed = 34.97 kph), with motorcycles travelling on average 3.3 kph faster than cars. Most motorcycles are travelling within the speed limit, but are 3.4 times more likely to be exceeding the speed limit than cars. Similar results are described for scooters. The mean speeds of all vehicles is less in the evening commuter time, and more so for motorcycles than any other type of vehicle. The presence of a car at the intersection did not affect mean speed. Motorcycles and scooters have a shorter headway to the vehicle in front, than any other vehicle type. The results are compared for robustness across locations and days. It is concluded that in urban areas motorcycles are travelling significantly faster than other traffic. These findings are discussed against a concern to reduce motorcycle crashes at intersections where the car driver is deemed ‘at fault’.