The A3102 is closed between Lyneham and Royal Wootton Bassett after a pedestrian was hit by a car earlier this evening.
Emergency services were called to the scene on The Green following reports of the serious injury crash outside the Texaco petrol station at around 6pm.
A male casualty was taken to Great Western Hospital with suspected serious injuries.
The council were instructed to close the road in both directions whilst specialist traffic officers carry out forensic collision investigation work.