Motorists have been advised to expect delays through until the end of August due to ongoing lane closures on the Buncrana Road, Caw and Claudy areas of Derry and at Ballykelly to facilitate ongoing gas and works.
The busy Buncrana Road has been reduced to one lane from Skeoge Link Roundabout to Temple Grove to facilitate gas installation works.
The works are being carried out by Firmus Energy and a traffic controls are in operation from 9.30am to 4.30pm.
The programme of gas works will continue through until August 31.
Meanwhile, after being halted for the Open golf tournament in Portrush, and the roadworks on Main Street in Ballykelly have resumed this week.
NI Water is upgrading the existing storm sewerage system in the town.
Works recommenced on Monday and will continue until the end of August, with works seven days a week, and extended working hours from 7am to 11pm.
NI Water said that following extensive consultations to minimise the works impact of these works on residents, businesses and road users, works have been programmed to be completed during the summer months when traffic flows are lightest, however some level of disruption should be expected.
Traffic flows through Ballykelly Village is via the use of temporary traffic controls.
Significant traffic delays are expected during these works, road users are advised to allow extra time for their journey, or if possible take an alternative route.
There are also a number of lanes closed on roads around the Claudy, while roadworks are also taking place in and around Caw Roundabout over the coming weeks.