Repairs to the parapet of a bridge over the River Nene will require temporary traffic lights to be erected nearby.
A car accident damaged stonework on the east side of Southbridge in Cotton End, which has seen part of the footpath cordoned off ever since.
Highways officers will now carry out safety repairs which begin on Sunday (September 16) and are estimated to last three weeks, with work taking place between 7.30am and 4.30pm.
A Northamptonshire County Council spokesman said the works will be carried out by using two-way temporary traffic signals throughout the project.
He said: "The temporary signals will be set up on the evening of Sunday, September 16 in order to start works immediately on Monday September 17.
"The temporary signals will be taken down following completion of the bridge repairs."
The footpath on the east side of the bridge will be closed during the works, and a pedestrian diversion will be in place, using pedestrian crossing facilities at either end of the bridge.
The spokesman said: "When programming works, we consider the impact on all road users and plan our works to minimise disruption.
"We'd like to thank you for your patience and co-operation."
For more information please go to www.northamptonshire.gov.uk