The rebuild of the bridge at Central Drive, Bloxwich, was unexpectedly put on hold by Network Rail last October.
But the project has been given the go-ahead to resume from today – with a road closure due to be in place for up to four months.
It comes as rail bosses have revealed the rebuild of another bridge in Walsall town centre has now been put back until autumn.
Structures on the Chase Line between Walsall and Rugeley need to be revamped to accommodate overhead power lines for the electrification.
Construction of the new bridge in Central Drive was suddenly halted last autumn for the potential impact of former mineshafts to be assessed.
The investigations have been completed and the scheme can get under way again. A signed diversion route will be in operation along Sneyd Hall Road, Sneyd Lane, Sandbank, Elmore Green Road and Croxdene Avenue.
Work to rebuild the bridge in Park Street, Walsall town centre, has now been rescheduled until October after complications to remove the existing structure were revealed.
Preparatory work started towards the end of last year and was temporarily stopped over the Christmas period.
It resumed last week but engineers discovered the bridge, which dates back to the 1930s, was different to the original plans, which means the planned removal of the structure by crane has to be reassessed.
That stage of the scheme is now due to take place between October and spring 2016 although bosses insist the overall electrification will be completed by the end of 2017 as planned.
Liam Sumpter, area director for Network Rail, said: "Electrification provides a greener, faster and more reliable railway, providing a better service to passengers.
"A significant amount of work is required to upgrade the railway and much is already underway or completed as part of our investment.
"Replacing these bridges is essential to allow the line to be electrified and while there will be disruption while the upgrades are completed the end result will be a better railway for Walsall and the wider West Midlands."
The Chase Line runs through Hednesford, Cannock, Landywood and Bloxwich. The project will see the installation of 15 miles of overhead cables and diesel trains will also be replaced by electric ones.