Motorists were being warned of long delays after a head-on crash blocked the A14.
Highways England said the collision was westbound at Junction 28 (Swavesey) between the services and slip road.
It said: “Expect long delays and approach with caution.”
A Cambridgeshire police spokeswoman said: “We were called at 2.17pm today to reports of a collision involving two vehicles on the A14 at Boxworth near Cambridge Services.
“As a result the road is currently blocked westbound.
“Officers are currently at the scene together with paramedics.”
Highways England has now confirmed that the road has reopened.