Diversions are in place to allow emergency services to deal with the crash on the A66 at Threlkeld, near Keswick.
Travelling towards west Cumbria, motorists are advised to use junction 41 of the M6, travelling along the B5305, Wigton.
Travelling towards Penrith, motorists should follow the diversions in place at the Crossthwaite roundabout, Keswick.
Cumbria Police say that the road will be closed for some time.
The A66 has been closed at Threlkeld following a collision involving a car and a cyclist.
Emergency services are currently at the scene at the junction with Threlkeld, near Keswick.
The extent of the cyclist's injuries are not known at this time.
Motorists are being advised to avoid the area and to seek alternative routes.
The family of a man who is in intensive care after a road crash on Valentine's Day are urging witnesses to come forward.
The crash happened around two miles east of the Sportman on the A66.
23-year-old Steven Higgins from Carlisle has serious injuries and is unable to communicate.
Police would like to speak to the driver of a blue BMW spotted at the scene.
Steven's family have been keeping a vigil by his bedside, and his sister Natalie Higgins is staying positive:
A 52 year old lorry driver accused of causing the death of two soldiers has pleaded not guilty to death by dangerous driving.
Lance Sergeant David Gartland aged 40, and Private James Austin aged 24, died in the accident on the A66 near Stainmore in September 2011.
At Carlisle Crown Court, Colin Pattinson entered a not guilty plea and will now face trial in September.
The two soldiers had spent the day at the Warcop Firing Range near Appleby and were heading back to their base at Catterick Garrison in an army Land Rover ambulance when the accident happened.
Police are looking to speak to the driver of a blue BMW, believed to have been involved in a serious accident on the A66 this morning (14th February):