The A66 is closed westbound between the A591 at Keswick and the A5086 near Embleton while police deal with a serious collision.
The crash is believed to involve four vehicles.
The road is currently closed between the Oakhurst roundabout and the A66 turn off for Dubwath.
A diversion is in place and road users are being advised to follow a westbound diversion route following the hollow triangle symbol.
Delays are likely on the approach to the closure, with additional journey times also expected on diversion routes.
Road users are advised to allow extra journey time if travelling in the area.
