Cutting speed limits to 20mph has 'little impact on road safety' - in part because drivers don't obey the rules

16 November 2022, 09:37

Cutting speed limits has little effect on road safety, a study has found
Cutting speed limits has little effect on road safety, a study has found. Picture: Getty

By Kit Heren

Cutting speed limits to 20mph does not significantly increase road safety, partly because drivers don't stick to the rules, a new report has found.

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Schemes to cut speed limits to 20mph have become more popular in the UK and other parts of Europe in recent years to bring down the numbers of people killed or injured on the road.

But a study looking at 76 roads in Belfast before and after the 20mph speed limit was introduced found that bringing the speed limit down from 30mph or 40mph had little impact on the number of crashes, casualty rates or average traffic speed.

20mph speed limits have been brought in in much of the UK
20mph speed limits have been brought in in much of the UK. Picture: Getty

This goes against other reports into road safety, which have found that lower speed limits have helped with road safety.

But the authors of the new study did find that roads with the 20mph speed limit had fewer cars driving on them.

RAC road safety spokesman Simon Williams said: "The findings of this study are surprising as they appear to suggest that drivers on 20mph roads in Belfast hardly slowed down at all, despite the lower speed limit, which is at odds with other reports.

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"It seems there is a serious problem with compliance as we would expect that even without enforcement, average speeds would drop.

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"Consequently, the study may demonstrate a need for councils to find other ways to get drivers to slow down, whether that's through enforcement or modifying road design with traffic islands, well-designed speed humps or chicanes."

Authors of the report, published in the Journal of Epidemiology and Community Health, suggested that 20mph limits could be combined with other measures such as driver training, CCTV and police communications to "facilitate an ambitious culture change that shifts populations away from the car-dominant paradigm".

It added that reducing speed limits is "not simply a road-safety intervention" but can be "part of the fundamental reset of the way we choose our life priorities - people before cars".

'The cyclists just speed on by, no one is accountable.'

Among UK initiatives to bring down speed limits, the Welsh government has committed to lowering speed limits to 20mph on all roads in the country where cars mix with pedestrians and cyclists.

Mary Williams, chief executive of road safety charity Brake, described 20mph limits as "life-saving", particularly for pedestrians and people riding bicycles and motorbikes.

She went on: "It is a matter of physics. At speeds of 20mph or less, drivers have significantly more chance to spot hazards and stop in time.

"The difference between a 20mph limit and a 30mph limit is a doubled stopping distance."