Roadside versus in-car speed support for a green wave : a driving simulator study

green wave on a road with a series of coupled signalised intersections enables a driver to pass each traffic light at green light. So he/she does not have to stop. A green wave is an advantage for drivers, through-put and safety on the road network and the environment. At coupled signalised intersections, the driver will get green light at the intersections driving a given speed. Therefore, the driver needs information about the speed he/she has to drive. Variable message signs are already used for giving drivers a speed advice for a green wave. The use of an in-car display for a green wave is new. The given green wave speed advice is adjusted to the current status of the traffic lights. In this study, two systems providing the driver a green wave advice were investigated. These two systems were variable message signs at the roadside and an in-car display.