Highways officials have re-opened a stretch of the A1 near Brampton Hut after following a two-car collision this morning (Friday).
Police were called at about 9.15am to reports that two cars had collided on A1, at its junction with the A14, at Brampton Hut.
One of the vehicles, a Land Rover Discovery, overturned after reportedly colliding with a police firearms vehicle. There were no reports of any serious injuries.
Highways England closed the northbound carriageway while emergency services work to clear the scene.
A spokesman for Cambridgeshire police said investigations into the collision had been completed and the road re-opened to traffic at about 1pm.
Motorists are being advised to expect delays while traffic flows return to normal.