One person has been injured in a four vehicle collision on the Fletton Parkway at Hampton.
The crash happened at about 5.30pm at junction three of the parkway on the eastbound carriageway.
A Cambridgeshire police spokesman said: “There are four vehicles involved.
“There has been one casualty, who is conscious and breathing.”
The queues stretch back to the A1 slip road.
Motorists are being warned to expect long delays in the area while emergency services work at the scene.