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Speed Limits: Urban Areas

Question for Department for Transport

UIN 198586, tabled on 4 June 2014

To ask the Secretary of State for Transport, what assessment his Department has made of the potential effect of changing the national urban default speed limit to 20 mph on (a) air pollution and (b) other environmental conditions; what similar studies in other developed nations his Department has assessed; and if he will make a statement.

Answered on

12 June 2014

The Department does not have any current plans to introduce a default 20mph speed limit. Local authorities are best placed to determine the speed limits for their areas, based on local knowledge and the views of the community, and have the powers to do so. We are aware of studies carried out for local authorities, including for the City of London, which showed no overall negative effects on air quality in 20mph speed restrictions.

However, the Department is about to commission comprehensive research into the effects of 20mph limits. This will cover many aspects including effects on speed, collisions, casualties and modal shift. The research will also consider air quality, best practice, road users' perceptions and effects on the quality of the environment, as well as relevant research from other countries.