Commuters who use Highway 126 are being forced to use a detour after a washout in the Lutes Mountain area, just north of Moncton.
The road closure lies between Briggs Cross Road and Indian Mountain Road.
The Department of Transportation and Infrastructure says the deluge from Dorian washed out a culvert and work is underway to replace it.
That section may not reopen until late November but DTI spokesperson Jeremy Trevors says an exact timeline should be known in a few days.
Drivers are being rerouted to Indian Mountain Road through Communication Road and onto Highway 115.
Trucks are being advised to use Route 11 instead of Highway 126 between Moncton and Miramichi.
For the latest road conditions, visit 511.gnb.ca/en/