Work to repair and improve drainage along a mile-long section of the M6 in Lancashire is due to begin next month.
The £270,000 Highways Agency scheme will tackle the worn drainage system in the hard shoulder and central reservation of the southbound carriageway, between junction 34 at Lancaster and junction 33 at Galgate.
Bosses said the project was essential, and assured commuters the work would be done outside of peak times.
Peter Gee, Highways Agency project sponsor, said: “This is vital work to upgrade the drainage system along a short stretch of the southbound carriageway and reduce the potential for surface flooding during heavy downpours as well as run-off into neighbouring fields.
“We will be doing the work outside peak travel hours during the day to minimise disruption to motorway users.”
The work, just north of junction 33, will start on Monday September 15 and is expected to be completed by Monday September 22.
All the work will be taking place between 10am and 3.30pm each day, with either lane one or lane three closed over a short stretch of the carriageway.
A 50mph speed limit will be in place for safety reasons past the roadworks.
Highways Agency chiefs said management and improvement projects were planned carefully so they could be completed safely and in a cost-effective way, “while keeping disruption to road users to a minimum”.
They said they did as much work as possible overnight and when roads were less busy, in order to keep more lanes open for road users at peak travel times.
Drivers are advised to check their route for roadworks and allow extra time.
Traffic information for the motorways and key roads is available online at www.highways.gov.uk/traffic.