All the emergency services are on the scene of a crash near the turning for Bromholme Lane in Huntingdon.
Bromholme Lane is the road that leads to Brampton Mill, off Huntingdon Road.
There are queues of around one mile and drivers have been warned to approach the area with caution or find an alternative route.
Cambridgeshire police said they were called at 12.58pm to reports of a collision involving two cars on Bromholme Lane, at the junction with the B1514, Brampton.
"One person suffered minor injuries. Officers are assisting with traffic control," according to police.
The ambulance service also attended and said they did not take anyone to hospital for treatment.