Drivers are facing six months of roadworks and speed restrictions while one of the busiest traffic islands on one of the main commuter routes into Birmingham is rebuilt at a cost of £3 million.
Highways Agency chiefs are aiming to widen Bassetts Pole, near Sutton Coldfield, to three lanes and install traffic lights, which they claim will improve traffic flow.
Extra lighting and safety barriers will also be installed to improve safety.
In a bid to minimise disruption work is being carried out during off-peak times, with overnight and weekend total closures when traffic will be diverted.
Throughout the work a 30mph speed limit will be introduced.
Karen Green, Highways Agency project manager, said: "We have carefully planned these essential upgrades of the A38 to be carried out as efficiently and safely as possible.
"Although occasional closures will be necessary at both sites, these are being carried out overnight when traffic is flows are lower. Road users should allow extra time for their journeys."
A further scheme has also been announced for the A38 in Staffordshire with £1.8 million spent resurfacing the road between Hilliards Cross, south of Alrewas, and the Swinfen Island interchange. This work starts on January 9.
The work will be carried out overnight from 8pm to 6am and during weekends, 8pm on Friday through to 6am on Monday.