Heavy goods vehicles are now banned from using the B440 through Water End and Great Gaddesden.
The 7.5-tonne limit follows a campaign by local residents concerned by the effects of HGVs using the road through the villages as a cut through.
As well as the noise and vibration, lorries were sometimes striking the historic bridge across the River Gade in Water End, which was costing the county council thousands of pounds to repair.
However the opening of the new A5-M1 Link, also known as the Dunstable Northern Bypass, has allowed Herts County Council, Bucks County Council and Central Bedfordshire Council to reclassify the A4146 between Galley Hill and just south of Leighton Buzzard, and renumber it as the B440.
The county council has also worked with residents to design and implement a 7.5-tonne weight limit to prevent HGVs using the reclassified route. Legal orders have now been completed and new road signs are up along the route, making the ban enforceable by the police.
Phil Bibby, cabinet member for highways at County Hall, said: “I know residents have felt strongly about this issue for a long time, and we’ve listened to those concerns.
“I’m confident that the new regulations will make a noticeable difference in the villages, from reduced noise pollution to protecting the historic bridge in Water End.”
