Review of traffic calming schemes in 20 mph zones (TRL Report 215)

  • Published: Transport Research Laboratory, 1996
  • Authors: D. Webster and A. Mackie
  • Date Added: 02 Feb 2013
  • Last Update: 04 Jul 2014
  • Format: html


A review for the Department of Transport [sic] to ascertain the effects of traffic calming using 20 mph zones.


Literature review.

Key Findings:

  • The frequency of all RTIs was reduced when ’20 mph zones’ were introduced – by 60 per cent overall, 63 per cent for pedestrians and 67 per cent for all child RTIs.

  • Overall vehicle speeds fell by 9.3 mph on average.


Pedestrian safety, engineering, enforcement, 20 mph, traffic calming


Despite the age of this report it is still cited with regard to application of 20 mph zones (for example, the Forty Ninth Report of the Public Accounts Committee in 2009 cites these figures).