Skip to main content

M4 Smart Motorway (Junctions 3 to 12) Upgrade

Client: (BBV JV) Balfour Beatty, VINCI.

This Highways England project will improve the M4 by making it a smart motorway. The M4 carries an average of 130,000 vehicles a day, and this section of the motorway is frequently congested. New signs and signals will be used to vary the speed limit to reduce congestion at busy times.

They will also control traffic if there is an obstruction on the road ahead. In the longest smart motorway project in England to date (51km), the motorway will be widened to four lanes in both directions. The hard shoulder will be removed and there will be adjustments to slip roads and motorway intersections between junctions 3 (Hayes) and 12 (Theale). New signage and smart technology will enable proactive management of the motorway in the event of heavy traffic or accidents.

Awards: Top 3% Health & Safety, Leading Women Pilot (link to project story), Balfour Beatty increasing the percentage of women on Highways projects.

Project in numbers

vehicles a day
stretch of smart motorway