Two people were cut from a car and taken to Watford General Hospital after hitting the M1’s central reservation in the fog.
Rescue workers rushed to help the man and woman after being called to Junction 7 of the southbound M1 in the early hours of this morning.
Police shut the fast and middle lane of the motorway while firefighters cut the roof off the silver Vauxhall Astra to free the pair after a 999 call at about 12.40am.
Police spokesman Olivia Finucane said: “It was very, very foggy on the road.”
The two people in the car had minor neck and chest pains.
Hemel Hempstead Fire Station watch commander Andy Esson said: “The emergency services advise people to take extra care in poor weather conditions.”