A project to improve Bradford Street bridge will start on Monday, July 25.
The existing barriers on the bridge will be replaced with improved steel railings.
The work is expected to take four weeks to complete subject to weather conditions.
Bradford Street will remain open to traffic at all times but for the safety of motorists and workers on site, one lane in each direction will be closed for the duration of the scheme.
Motorists are warned delays are likely and to use alternative routes.
Bolton Council’s Cabinet Member for Highways, Cllr Elaine Sherrington, said: “We are doing the work in the school holidays in an effort to minimise disruption.
“We would like to apologise in advance for any inconvenience and thank drivers for their patience.”
The work is being funded from a grant awarded by the government for improvements to St Peter’s Way.
For more information, residents can contact the council via e-mail firstname.lastname@example.org.