A 60-year-old man from Florida has been taken to hospital in Newcastle with "serious injuries", after his bike collided with a car on the A66.
The accident happened at Threlkeld, near Keswick.
The driver of the car was uninjured in the accident.
Motorists are asked to follow the diversions in place.
More top news
Kerrie brings you Saturday night's forecast
High pressure keeps things dry and warm - but for how long?
Tim Backshall reports on the battle of Arnhem as part of the 75th anniversary commemorations.