A man was airlifted to hospital in a 'potentially critical condition' after crashing his car on the Uxbridge Road junction with Kingston Lane.
Emergency services, including the Metropolitan Police, London Ambulance Service and London Fire Brigade were called to the scene at around 2.45pm on Sunday (September 9) and the man, believed to be in his 50s, was lifted to hospital by London's Air Ambulance.
Uxbridge Road was closed in both directions and some road closures remain in place, creating delays on Cowley Road southbound and on Kingston Lane and The Greenway in both directions.
Hillingdon Police tweeted at 3pm that drivers should avoid the area as the road will be closed "for some time".
A London Fire Brigade spokeswoman said that the car collided with street furniture, which could have been a bollard or lampost. No other vehicles or persons were believed to be involved.
She added: "One man was released from the vehicle and was treated at the scene by London Ambulance Service. The incident was over for us at 3.25pm. We sent two fire engines and a fire rescue unit to the scene."
A police spokesman said: "We await a further update on the man's injuries and his next of kin have been informed.
"There have been no arrests and enquiries continue."