Motorists using the main route for Exmouth face months of road closures, diversions, temporary one-way routes and disruption to reach the town.
County road chiefs have announced the new Dinan Way extension will open on Wednesday, September 9, but revealed some disruption for drivers until the end of the year while the final phase of work is finished.
Motorists will be diverted in and out of Exmouth until the end of December, turning residential roads into one-way traffic systems.
A short section of the A376 between Courtlands Cross and Courtlands Lane will close to through-traffic while the roundabout is completed.
The new 800-metre road will open for traffic in and out of Exmouth while the second new roundabout is finished at the A376 junction.
There will be overnight closures at Courtlands Cross from 7pm until 6am on September 7 and September 8 for preparation work to be carried out.
And 57 and 96 bus routes will be temporarily suspended from September 9 until December 4 from the Hulham Road junction up to the A376 closure. Alternative routes are through Hulham Road, Dinan Way. Bus stops will be transferred to Hulham Road.
During the closures, vehicles travelling to and from Exmouth town centre will be diverted along the newly-completed Dinan Way extension and Hulham Road, with a number of temporary one-way routes.
HGV vehicles transporting extra wide loads will not use the diversion routes, said DCC. They will follow A3052, B3180 and B3179 routes to reach Exmouth.
The Devon County Council diversion, closure and one-way routes. Image: DCC.
Devon County Council (DCC) said the aim of the one-way system was so most residents can continue to park on the road in a bid to keep congestion on Hulham Road to a minimum.
DCC said some parking restrictions were necessary, outside Hulham Road stores and at the nearby junction with Exeter Road, where the road narrows.
And parking restrictions are planned for A376 between Courtlands Lane junction and Rivermead Avenue for pavement widening.
Temporary traffic lights will be on parts of the A376 during the autumn while contractors divert utility services, finish drainage, kerbs and pavements.
The dates and timescales for road closures, diversions, temporary one-way routes are:
The county council said the new road would improve local journeys, support future housing at Goodmores Farm and provide a safer, more reliable route.
Councillor Dan Thomas, DCC cabinet member for highways, said: “Opening the Dinan Way link road is a major step forward. It means we can begin the final stage of work while keeping traffic moving in and out of Exmouth.
“We know the temporary closure of part of the A376 will mean changes for road users, but using the new road as the diversion route will help us build the roundabout safely and as quickly as possible.
“Once complete, the scheme will bring lasting benefits for residents, businesses and visitors.”
The county council said the A376 roundabout was one of the most difficult parts of the build.
Dinan Way Extension Opening Brings Months of Exmouth Road Disruption