Impact of road humps on vehicles and their occupants

A study has been undertaken by TRL and Millbrook Proving Ground for the Charging and Local Transport Division of the Department for Transport (DfT) to examine the impact of road humps on vehicles and their occupants. It involved testing of vehicles driven repeatedly over road humps, computer modelling of the road humps and vehicles, and biomechanical modelling of the human spine. Road humps have been shown in a number of studies to reduce vehicle speeds and accident frequency. They are the most effective traffic calming device currently available and are likely to be in common use for some time. In general, levels of discomfort are higher when humps are traversed at higher speeds and therefore humps cause discomfort to vehicle occupants if their vehicle is travelling too fast. This increased discomfort is the mechanism which persuades drivers to slow down. The widespread use of road humps has resulted in some members of the public complaining that humps cause long term damage to vehicle components, especially the suspension, and that they can cause damage to the undersides of vehicles with low ground clearance or to exhausts. Concern has also been raised about whether the use of road humps might cause or exacerbate back or other injuries. The study aimed to investigate objectively the possibility that road humps cause increased wear to vehicle components and injury to vehicle occupants and to suggest how these problems, if they exist, can be ameliorated.