The retarders or speed bumps are devices for limiting the speed of the roadway portions in order to ensure the safety of all road users. Excessive speed generates half of the accidents in urban areas: it is one of the most important factors of road insecurity. It is also the main cause of seriousness during an accident: the higher the speed of circulation, the more serious the accident. A set of traffic equipment makes it possible to regulate the speed on the tracks.
There are several kinds of retarders suitable for public roads:
- Donkey type speed reducers, which have a long, circular profile
- The trapezoidal type retarders, which include a raised platform and two sloping parts
- The cushions and trays. The Berlin cushions, in particular, are trapezoidal rubber devices, the cushioning of which forces the drivers to slow down
In some municipalities, road equipment is oversized to make it more efficient, without taking into account the regulations in force. They are thus too high, too steep or not signaled.
What Regulations for Retarders
- Cannot be isolated and must be combined or with other arrangements moderating speed
- Must be spaced at a maximum of 150 meters from each other or other amenities
- Can only be installed in built-up areas, on-road or motorway service or rest areas, on forest roads or roads occasionally limited to 30 km / h or located in area 30
- Are prohibited within 200 meters of an agglomeration entrance or a section limited to 70 km / h
- Are prohibited on Highways (RGC) on lanes where heavy goods vehicle traffic is more than 300 vehicles per day and where all vehicle traffic is more than 300 vehicles per day, on regular public transport lines, or the routes serving emergency services