The M49 will be closed this weekend to allow a new bridge to be lifted into place.
A giant 500-tonne crane will be used to manoeuvre three bridge beams into place, with two 55-tonne cranes installing the decking.
The new bridge, which will be in place immediately next to the existing bridge at Farm Lane, is part of work to create a new elevated junction on the M49.
These will be linked into a single roundabout spanning connecting with both the northbound and southbound carriageways.
Highways England are hoping the £49 million scheme will create thousands of jobs, reduce congestion and boost the south west economy when it is completed this winter.
Nick Aldworth, Highways England’s south west regional delivery director said: “The bridge installation marks a significant milestone for this strategically and economically important scheme.
“Its proximity to the motorway network, railways and port makes it an ideal area to develop and encourage economic growth, and the road scheme has a phenomenally high benefit. Every £1 invested in this scheme will bring more than £30 into the local economy, generating more than 14,000 jobs in the long term.”
“I’m delighted to reach this stage of the project, and we’re pleased to share the occasion with our local authority partners, business leaders and local communities.
“The weekend closure of the M49 is essential to enable this work to be carried out and in the meantime we thank all motorists for their patience.
The M49 will be closed from 8pm on Friday to 6am on Monday. Diversions will be in place via the M4 and M5.