The access bridge for Turner’s Farm, which crosses the M6 at Barnacre between junction 32 and 33, will close overnight on Sunday and Monday (August 22 and 23).
The closures will take place from 9pm to 6am each night – with a diversion running along the A6 from junction 33 at Galgate and junction 32 via junction 1 of the M55 at Broughton.
The private ‘accommodation’ bridge links farmland on either side of the motorway and temporary supports were installed after a serious lorry crash in 2018.
These were replaced last week with a new permanent support column after new foundations were built in the verge alongside the southbound carriageway.
Highways England has been busy working on the bridge since April and 50mph speed limits have been in force along the stretch of motorway.
But all roadworks and speed safety cameras are expected to be removed by the middle of next week - just in time for the August bank holiday getaway.
Highways England project manager Chris Riley said: "We’ve worked hard to minimise delays to traffic travelling under the bridge and have done most of the work overnight relying on lane closures.
"We’ve already removed the temporary propping system this week and the bridge is now fully supported by the new permanent structure.
"To complete the work we will need to close the southbound carriageway of the M6 overnight for two nights on Sunday and Monday."
Highways England said it will be lifting as many roadworks as possible across the country at the end of next week to help people with their bank holiday journeys.
Mr Riley added: "We’d like to thank motorway users for their patience while we’ve worked to complete these repairs – the good news is that all the roadworks, including the 50mph speed limit and safety cameras, will be gone by Thursday."