The collision, which involved a black BMW 320, a yellow Mercedes Sprinter and three HGVs, happened at about 8.40am yesterday (23 August).
Officers, paramedics, fire crews and the air ambulance all attended the scene.
A man in his 20s who was driving the BMW was taken to hospital with serious injuries. He continues to receive treatment at Addenbrooke’s Hospital in Cambridge.
The driver of the Mercedes, a man in his 20s, received minor injuries and was also taken to hospital.
Police are appealing for anyone who witnessed the collision, has dashcam footage, or believes they may have seen the vehicles in the build up to it, to come forward.
Anyone with information is urged to contact police via their web chat service https://bit.ly/3vsiYDw or online forms at www.cambs.police.uk/report quoting incident 105 of 23 August. Anyone without internet access should call 101. Always dial 999 in an emergency.