Shropshire Council is currently creating a second roundabout off the Mile End junction in Oswestry, which will fundamentally alter the way the busy roundabout works.
The project, being carried out with Balfour Beatty, will also create a dedicated entrance to the council's new Oswestry Innovation Park.
The changes are also required to cope with the increased level of traffic expected from new housing sites.
The new roundabout will sit alongside Mile End Roundabout to the north.
It will have four exits and will take traffic from the A5, bypassing the existing Mile End Roundabout.
Motorists driving from Shrewsbury to North Wales – or vice versa – will be separated off to use the new roundabout to continue their journey.
One of the ambitions of the scheme is that by taking the A5 traffic out of the Mile End flow, it will significantly reduce congestion and speed up journey times.
It is anticipated that the work on the project will be completed in spring next year.
The work is the latest of a series of major changes at the roundabout which have cost millions of pounds in recent years.
The island was rebuilt at a cost of £4 million in 2014 only for the road markings to be redrawn in 2018 due to complaints that the roundabout's layout was confusing.