Continuing work on the West Coast Main Line rail improvements will mean delays and diversions for motorists using the A38 in Staffordshire over the next year.
As part of the upgrade the bridge carrying the A38 trunk road over the railway at Lichfield will be rebuilt.
It will mean speed restrictions over the bridge and diversions while roads and lanes near it are alternately closed.
The improvements are part of Network Rail's Trent Valley Four Tracking Project (TV4) and work at and around the bridge, which starts next month, will continue until August 2007.
Senior programme manager for Network Rail's TV4 project, Keith Riley, said: "This is the last bridge in the TV4 project that we need to rebuild, and it poses some major logistical construction challenges.
"We are working hard to make sure disruption to motorists is kept to a minimum, but they may experience some delay.
During the work, speed restriction of 40 miles an hour will be in place for the safety of motorists and workers.
From next month until March all southbound traffic will be diverted onto the northbound carriageway, maintaining two narrow lanes of traffic in each direction, whilst the east side of the bridge is demolished and rebuilt.
From March to June all northbound traffic will be diverted to the new southbound carriageway, maintaining two narrow lanes of traffic in each direction, whilst the west side of the bridge is demolished and rebuilt.
On completion of the north and southbound carriageways in June traffic management will continue to allow completion of the central reservation.
Four narrow lanes will be available.