Seven average speed cameras have been positioned along the stretch of the A17 that saw a 21-year-old killed in a car accidentjust before Christmas.
The cameras are sited between King’s Lynn and Sutton Bridge, though they are not yet operational.
The move follows a series of serious and fatal collisions on the A17 in recent years.
In the latest case, 21-year-old Laura Pesterfield, of Kirton, was killed when her car was in collision with a lorry at the junction with Station Road, Terrington St Clement, just four days before Christmas.
Laura was a care worker at the White Gables nursing home in Kirton and was studying with hopes of going to university.
Her two nephews were also injured in the tragedy, which saw more than 5,000 people sign an online petition calling for a roundabout.
A camera has been placed on each side of that junction, with two more installed close to the junction with Station Road, Clenchwarton.
A fifth camera is in place near the Pullover roundabout, King’s Lynn, with the other two sited at the western end of the route, near to turnings for Walpole Cross Keys and Walpole St Andrew.
Anne Pointin, police safety camera team manager, said the route had been identified as a top priority because of its crash history. She said: “It was felt the best intervention would be average speed cameras.”
MP for the area Sir Henry Bellingham welcomed the news but said he would still like to see the speed limit lowered to 40 miles per hour around junctions along the route.
However, although average speed camera systems are becoming a more attractive option because of reducing costs, they are only able to monitor one speed limit along the stretch of road covered.
Miss Pointin said: “If the highway authority feels the limit needed to be altered, they would do that and we would adjust the cameras accordingly.”