M4 Junction 3-12 Smart Motorway Team complete most complex piece of engineering to date

One weekend closure. 400 tonnes of steelwork. One River Thames diversion. One stunning sunrise. One bridge widened: the M4 smart motorway upgrade has hit its halfway point with its most complex work yet.

Creating extra lanes on the M4 requires replacing 11 bridges over the M4 so they are wide enough to fit the upgraded motorway, which, when finished will add vital extra capacity and improve journeys for the 140,000 drivers which use the motorway each day.

The Thames Bray bridge was different. It doesnt carry a local road or footbridge over the M4, it carries the motorway over the River Thames. An innovative solution was needed to widen the road in order to accommodate the smart motorway. The only option was to build the extended bridge elements on a nearby site and then assemble them over a single weekend to accommodate the extra lanes required for the four running lanes on each side of a smart motorway.

The Balfour Beatty VINCI team worked with Cleveland Bridge to successfully complete the work on behalf of Highways England. The installation of the three bridge beams, which formed the bulk of the work, was completed over the weekend of 30 May-1 June, with the remaining work finished the following weekend.

Julian Gatward, Taylor Woodrow Managing Director, said: Thank you for all your engineering prowess, fastidiousness to detail and sheer hard work. What a team to be proud of.

Shaun Pidcock, Highways Englands Smart Motorway Programme Director said: Not only is this one of the most complex tasks ever carried out on the strategic network, the team also had to contend with social distancing, the extremely hot weather, and the added challenge of making sure all was kept to plan so that the M4 was ready and open by Monday morning. This is an exceptional achievement for everyone involved.

Visit the project page to view a film of the works.

Notes: Balfour Beatty VINCI JV is made up of Balfour Beatty, Taylor Woodrow and VINCI Construction Grands Projets.