There are delays on the A1 northbound following a collision near Stibbington.
Emergency services were called to the incident at 3.05pm today (Friday).
A spokeswoman for Cambridgeshire police said the incident involved one vehicle, and injuries had been reported - but it was not clear how serious the injuries were.
Delays are expected in the area while emergency services work at the scene.
Motorists are advised to avoid the area.