Disruption on the A399 will begin in earnest next week as the busy road will go down to two lanes for four days.
West Berkshire Council is advising drivers to allow extra time for their journeys or use a different route. Alternatively, it recommends making short journeys across town on foot, especially at lunch times when the roads tend to be busier.
Council contractors will begin reconstructing the central reservation on the busy stretch of road next week, meaning that the lane closures will be in place between 9.30am and 3.30pm.
The outside lane will be closed in each direction on Monday and Tuesday between this times.
Then, on Thursday and Friday, the northbound outside lane for kerb installation. The inside southbound lane will be closed for ducting and cabling work, street light installation and footpath surfacing.
There will be no lane closures on Wednesday as traffic is expected to be higher because of racing at Newbury Racecourse.
Next week's works are the second of a nine week fixture of lane closures.
Last week's work's saw contractors finish the resurfacing of the main carriageway, with the council saying that there was minimal traffic disruption.
Steps on the western side of the canal bridge will also reopen next week.
The work is part of a West Berkshire Council scheme to construct a new junction on the A339 to Faraday Road.
The signal-controlled junction, south of the Robin Hood Roundabout, will see a new crossing for pedestrians and cyclists that will link directly with a new, additional, entrance to Victoria Park.
West Berkshire Council has said the new junction will improve traffic flow along the A339 by reducing the number of vehicles using the Robin Hood Roundabout.