The A66 is closed westbound due to a serious collision.
The route is shut from Scotch Corner to the A67 Barnard Castle junction.
North Yorkshire Police are on scene.
Highways England says road users intending on using the A66 westbound from the A1(M) are advised to plan ahead and use alternative routes.
Motorists are being advised to expect disruption and to allow extra journey time.
Further incident information is available at the Traffic England website.
The #A66 westbound #ScotchCorner #A1M (#A1MNorth #Newcastle) to #A67W (#BarnardCastle) is currently CLOSED due to a serious collision. If planning travel, avoid the area. Updates to follow… pic.twitter.com/aCVfn4E7OA
— Highways England (@HighwaysNEAST) January 6, 2021