M4 Smart Motorway

Work has commenced on construction of the M4 Smart motorway between junctions 3 and 12.

This is the longest smart motorway project in England to date (51km, 32 miles). To minimise disruption work will take place on different stages at different times.

Main aspects of the scheme are as follows:

  • Use of the latest technology to monitor traffic flow and set speed limits accordingly in order to keep traffic moving smoothly
  • Information about road conditions and speed limits will be displayed on electronic road signs
  • The hard shoulder will be converted to a permanent traffic lane to create additional capacity.

The current intention for the phasing of construction, is to start at junction 8/9 and progress west towards junction 10. In tandem work will take place on four bridges between junction 8/9 and junction 7. The more complex section of the scheme, progressing east from junction 8/9 towards junction 3, will be started in May 2019.

The current timetable has work starting on junction 12 to 11 in May 2020 and completing February 2022.

More information, can be found at the following site:


The latest newsletter can be found here:

Newsletter – March 2019