London, 8 Dec 1996.
For immediate release.

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Official: Low Non-Urban Speed Limits Cost Lives
US research confirms counter-productive effect of lowering speed limits

A report by the US Department of Transport's Federal Highway Administration (FHA) in 1992 confirms that unreasonably low speed limits in non-urban areas are counter-productive in road safety terms.

The FHA research shows that imposing limits which drivers perceive as unreasonable leads to high levels of non-compliance and - which is even worse in road safety terms - to an increase in accidents and above all to fatalities. On the other hand, raising speed limits to levels which most drivers observe anyway led to a high degree of compliance and to a significant reduction in the number of accidents.

The FHA studied vehicle speeds at 100 sites in 22 states before and after speed limits were changed, some being lowered and others raised. Where the limits were brought down below levels that most drivers thought were reasonable, observed speeds did not decrease and in many cases drivers actually increased their speeds. As a consequence, the levels of non-compliance increased. At the 58 sites where speed limits were reduced, accidents increased by 5.4 per cent.

Where speed limits were raised in line with the actual speeds observed by drivers (which on a UK motorway would be around 85 mph), levels of compliance naturally increased but, more significantly, at the 41 sites concerned accidents actually fell by 6.7 per cent.

The FHA research supports the ABD's long-term contention that inappropriate speed limits have a harmful effect on road accident statistics and on respect for the law in general. Of course, some local authorities have found that there are revenue benefits to be gained from setting and enforcing unreasonably low speed limits but the evidence now suggests that these authorities are, in effect, raising money at the expense of road safety.

 

Notes for Editors