Two people have been taken to Hillingdon Hospital following a crash involving three cars near the Hillingdon Circus A40 junction this afternoon.
The patients' conditions are unknown.
Emergency services were called around 1.55pm.
London Fire Brigade released two patients who were trapped in vehicles.
London Ambulance Service sent two ambulance crews and a duty officer to the scene and two the patients to hospital.
Police also attended. No arrests were made.
At 3.45pm the BBC Travel website was reporting two lanes blocked and queueing traffic on A40 eastbound in Hillingdon at Hillingdon Circus with congestion to Denham Roundabout
The crash happened just a day after another road incident in almost the same spot.
Around 5.20pm yesterday, there was a collision at the Freezeland Way and Hercies Road junction in Hillingdon.
And on July 30 a man in his 20s was taken to hospital following a lorry crash on the A40.