Part of the M5 near Bristol is to be closed overnight to allow a new bridge to be installed after the job was postponed last weekend.
Work was put off for health and safety reasons because of strong winds.
The motorway will be closed northbound at junction 18a. Southbound traffic should leave at junction 15 and follow a diversionary route via the M4.
Work will take place between 2000 GMT on Saturday and 1000 GMT on Sunday. The bridge will open four weeks later.
The previous bridge at Lawrence Weston was demolished in December 2009 after it had been damaged after being hit by a number of vehicles.
The new bridge, which will be used by pedestrians and cyclists, forms part of a traffic-free route towards the Bristol Channel, Severn Beach and into south Wales.