The A4 is closed in Calne as 999 crews attend a road traffic collision.
Emergency services were called to Black Dog Hill at around 2pm this afternoon (Tuesday).
The incident is believed to have involved a motorcyclist, who collided with the rear of a car.
Further details are unclear, but the road is closed in both directions.
A spokesperson for Wiltshire Police said: “A4 at Black dog Hill between Calne and Derry Hill is currently closed in both directions due to a road traffic collision.
“Please avoid the location and seek alternative routes.”