A road safety improvement scheme costing £1.1million will start at an accident blackspot on Monday.
Traffic lights are to be installed around the Sheraton junction of the A179 where it joins the A19 in response to a number of serious accidents and deaths.
Work is due to start on Monday and will continue until the spring.
Motorists are being advised to allow extra time for their journey.
Durham County Council is carrying out the work and said on its website: “We are installing traffic lights to reduce traffic queuing back onto the A19 from the northbound sliproad, and reducing the speed limit across the junction to 40mph.
“This will make it easier for drivers turning right at Sheraton junction.
“The work is taking place between October 2018 and Spring 2019.
“We are completing the work at off peak times when traffic is lighter.
“In recent years, there has been a number of serious accidents at this location, including fatalities.”
In total, the work is expected to last 25 weeks but the council says it is weather dependant and subject change.
The first phase is expected to take around four weeks and will involve lane closures on the north and south sliproads and temporary traffic lights.
Work will be carried out between 9.30am and 3pm and the council says the flow of traffic will be monitored to minimise disruption.
Times will change in further phases with some taking place overnight.
The council added: “At each phase of the works we will need to change the layout of the traffic management and details of this can be seen in the information below.
“When necessary some lane restrictions and road closures will be in place and diversions clearly sign posted.”
The Sheraton junction has been awarded £1.1million by Highways England to reduce congestion and improve safety.
The site was one of a number of traffic hotspots across England identified by Highways England for junction upgrades, roundabout improvements or better traffic signalling.
Highways England previously said: “This work which is being carried out by Durham County Council on our behalf will improve journey times, reduce congestion and improve safety.
“This improvement was announced in March 2017 as part of a £220 million Congestion Relief Fund.”
For more details see www.durham.gov.uk/sheraton