FIM Position: TRAFFIC CALMING DEVICES
Fédération Internationale de Motocyclisme
Speed is considered one of the most important causes of accidents, especially on urban roads or smaller roads in rural areas. Signs are often not enough to reduce speed and enforcement is either not always possible or the costs are considered to be too high. For this reason, the road authorities often choose to install traffic calming devices. These can be optical (road markings), horizontal (road width restrictions/chicanes) or vertical (speed bumps/rumble strips).
Why traffic calming devices can be dangerous for motorcycles
- Motorcycles are balancing vehicles, and loss of balance can be caused by a sudden vertical movement or a sudden lateral movement.
- Sudden vertical movements can be caused by excessive vehicle speed, excessive gradient or height of a speed bump.
- Motorcycles are single-track vehicles. This means, that they lose grip more suddenly than multi-track vehicles. Loss of grip can be caused by a slippery surface, but also by the sloping ends of a speed bump that does not run the entire width of the road or by the sloping ends of cushion shaped, or rounded speed bumps.
- When a motorcycle does not approach a speed bump at the appropriate angle, the motorcycle can lose grip, or the rider can lose his balance. This happens when a speed bump is installed in or near a bend, or when the speed bump has an abnormal shape.
- Horizontal calming devices can be dangerous when the shape is not in accordance with the current national regulations, when the markings are not clear under all circumstances or are situated in a bend or in other place with inadequate view.
How to install traffic calming devices that are safe for motorcycles
- Calming devices should always be designed and installed in a way that is in accordance with the current national regulations
- The calming devices should be well marked and signed and placed correctly, so they are visible for the road user under all circumstances.
- Calming devices should never be situated in a bend.
- The material of the calming devices should ensure enough grip under all circumstances.
- The gradient and height of a vertical calming device should never be greater than is strictly necessary.
- The vertical calming device or speed bump should never have a slope that runs lateral to the direction of an oncoming motorcycle, because it can lead to loss of balance.