A full road closure will be in place on a stretch of the Belfast Road in Newry until the end of August during resurfacing works.
A £300,000 scheme has started and work will extend a distance of approximately 800 metres, from its junction with Mourne Country roundabout to Maurice Murphy Car Sales.
To facilitate the works it will be necessary to operate a full road closure until Sunday, August 30, for southbound traffic and introduce a temporary one-way arrangement for northbound traffic.
A signed diversion will be in place for vehicles travelling southbound.
Cars and light commercial vehicles are being diverted via Carnbane Way, Armagh Road, Canal Street, and Downshire Road. Heavy Good Vehicles are being diverted via Dublin Road and Bridge Street.
A DofI spokesperson said: “The Department has carefully planned these road works and associated traffic management arrangements in order to minimise inconvenience to the public.
“Road users are advised to allow extra time for their journey and to follow the alternative routes which will be clearly signed on the approaches to the works.
“Completion of the scheme by August 30 is dependent on favourable weather conditions however the Department will keep the public informed of any change.
“All work will be carried out in line with current public health and health and safety advice, with safe systems of working in place for staff and contractors.”