Except for Croydon Road and Bushey Road, Merton roads are now subject to 20mph speed limit. All TfL roads are 30mph .

20mph zones

A legal and self-enforceable 20mph zone requires traffic calming features such as:

  • road humps
  • ​speed cushions
  • road closures
  • one-way systems
  • pedestrian refuge islands and road narrowing to be introduced at the appropriate distance

20mph zones prior to 2019

20mph speed limits

A 20mph limit does not require any traffic calming features as part of the legal requirements. It requires only the introduction of the appropriate signs and road markings at all the entry points into the area.

20mph speed limits prior to 2019

Monitoring Analysis 2012

Merton has a combination of roads with 20 mph limits and 20 mph zones, mainly implemented during the past 4 years. The council commissioned an analysis of the effectiveness of the current schemes focusing on accident data at each of the individual limits and zones before and after installation, along with before and after traffic flow and vehicle speed data.

Interim Monitoring Analysis - TMS Report - July 2012