An elderly woman has suffered "possible life-changing injuries" after she was hit by a vehicle in South Ruislip .
The incident which happened on Tuesday (November 29) resulted in motorists being stuck in traffic for almost four hours.
Officers said the female pedestrian, aged in her 70s, has been taken to a central London hospital with "possible life-changing injuries".
Police closed the road, reportedly between the Polish War Memorial and Station Approach, shortly after the collision before reopening it at 2.03pm.
However, motorists have reported that there is still heavy congestion in the area.
The force, who have made no arrests, added that the driver of the car stopped at the scene and is assisting police in their investigation as enquires continue.
A police spokesman said: "Police were called by London Ambulance Service to West End Road, South Ruislip, at 10.23am on Tuesday, 29 November to reports of a road traffic collision involving a pedestrian and a car.
"The female pedestrian, aged in her 70s, has been taken to a central London hospital with possible life-changing injuries.
"The driver of the car stopped at the scene and is assisting police with their investigation.
"The road re-opened at 2.03pm.
"No arrests have been made.
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