There are lengthy delays on the A14 near Hemingford Abbots after a collision on the eastbound carriageway.
The accident involving up to four vehicles took place at about 10.40am just after junction 25 on the stretch of road, with police closing one lane while the vehicles are moved from the road.
A spokesman for Cambridgeshire police said that no injuries have been reported following the collision but damage has occurred to the vehicles involved.
Congestion is currently stretching back to junction 26 for St Ives, and motorists can expect delays of up to 40 minutes.
Highways England has predicted that the incident is likely to be cleared by 12.30pm.
Motorists are advised to use alternative routes if possible.