Drivers were being urged to avoid the Greenford area on Wednesday afternoon (September 14) after a car overturned on the A40 causing the road to be closed out of London.
Reports of the crash first surfaced at about 1.30pm and Ealing police urged people to avoid the area due to the traffic caused by the incident.
The collision is believed to have happened when a car collided with a bollard and flipped.
A man was removed from the vehicle but his condition is unknown.
Traffic was being redirected off the slip road causing queues beyond the Polish War Memorial.
The road was reopened just before 3pm but traffic remained congested into the afternoon.
Police were called to the scene just before 1.30pm after the car collided with a bollard and overturned.
A spokesperson for the Metropolitan Police said: “A male was removed from the vehicle. We await an update on his condition.
“Officers attended and the London Fire Brigade and the London Ambulance Service were also called.
“A car was found to have collided with a bollard and overturned.”