These are raised sections of road which may be humpback or trapeze-shaped. They are speed calming measures that are more restrictive than speed cushions and speed tables. This is why they are the subject of a decree and a standard. Decree No.94-447 of 27 May 1994 makes it a requirement for speed bumps to conform to French standard NFP 98-300 of 16 May 1994 which sets out the geometric characteristics and procedures for building speed bumps and imposes restrictions on local authorities regarding their location. Trapezoidal speed bumps must be surmounted by a pedestrian crossing whereas this is prohibited in the case of humpback speed bumps.