Speed Limit Benefits

Some interesting statistics have emerged following the launching of a number of 20mph limits on roads in the Upper Calder Valley. Slower traffic speeds in built-up areas clearly have a positive influence on the experiences of vulnerable road users and pedestrians, including disabled people.

Calderdale’s Director of Public Health, Paul Butcher presented 20mph data in a report to the council’s Place Scrutiny Committee on 26 April.  Key findings were

  • 30% casualty reduction over a 3 year period and later schemes indicate a 40% reduction.  This equates to 154 fewer injuries – 51 from the 3 years data available (a statistically significant reduction). Plus 103 from the projected 3 years data for the later schemes.
  • Cost effective intervention – total investment of £821k from a West Yorkshire Local Transport Plan and Department of Health ring fenced grant. Given the reduction in injuries a public saving in the region of £3M  – based on the Department for Transport’s road traffic casualties slight injuries value of prevention of £23.5k per person.  This is a rate of return of £3.65 for every £1 spent (with future benefits for a minimal ongoing cost).
  • Cost was £1.6k per km of road
  • 1.9mph mean reduction in speed taken from 3.5 million+ readings with variations in some areas.
  • Continuing public support for 20mph (over 80%) from attitudinal surveys in Todmorden and Sowerby Bridge.
  • Police engagement and enforcement continues via Operation Hawmill which has fined 20mph offenders. 12 vehicle activated speeding signs are in use.