Earl Street in The Mounts area of Northampton will be closed for a fortnight from Monday because of sewer upgrades.
Anglian Water is continuing its £2.5 million project in Northampton to reline sewer pipes.
Sections under Earl Street are the latest to be addressed, and trenches will be dug along the road while the work is carried out.
Emma Staples from Anglian Water said: “In total, we’re fitting state-of-the-art liners to five-and-a-half kilometres of pipes in the town centre to protect the ageing brickwork and keep them flowing for decades to come - 70-metres of which is on Earl Street.
“The upgrade does mean there will be some unavoidable traffic disruption in the nearby area, and we’re sorry for that. However, we hope people will understand the importance of carrying out these improvements.
Earl Street will be closed, in two stages, for two weeks from August 12.
The junction between Earl Street and Robert Street will be closed for the entire duration.
The section of Earl Street north of this junction will be closed in week one, while the section south of the junction will be closed in week two.
Traffic moving west on Campbell Street will be able to turn onto Bailiff Street and Robert Street as normal. Road users travelling westbound on Campbell Street will be diverted via Overstone Street, Duke Street and Bailiff Street to access Robert Street.
Mrs Staples said: “Access to the rear of the fire and police stations will be maintained via this same diversion.
“However, emergency vehicles will continue to exit at the front of the stations, directly onto Campbell Street as normal.”
Anglian Water originally gave notice of work on April 7 and follow-up letters were sent to customers on July 29. A further letter to customers is being sent this week.