A driver and their passenger were taken to hospital after an accident on the narrow section of the A59 at Kex Gill, between Harrogate and Skipton.
Traffic Officer David Minto said that the car flipped onto its roof and the road had to be closed while emergency services dealt with the scene.
There were long tailbacks on the route and the Air Ambulance and the local MOD Police also assisted in the operation.
The driver received serious but not life threatening injuries in the crash.
The road is now open again.