The A1 northbound between the A603 and Black Cat roundabout and A421 westbound from Black Cat to A4280 will be closed from 10pm on Friday (27 February) until midday on Sunday (1 March) and 9pm Sunday 1 March to 6am Monday 2 March.
The road will be closed for resurfacing and to allow the existing roads surrounding the roundabout to be connected to the new section of roundabout which has been built.
There will be a clearly signed diversion route via the A603 and A421.
The A1 northbound between Blunham and Wyboston and A421 between Cardington and Black Cat will also be closed from 10pm on Friday 6 March until midday on Sunday 8 March. Drivers travelling along the A1 will be diverted via Barford Road and A428 and drivers travelling along the A421 will be diverted along A603.
Drivers intending to travel on the A1 or A421 are advised to plan their journeys and allow some extra time to reach their destinations.
The scheme to ease congestion at this important roundabout is on track to complete by the end of March.
It is part of the Government’s £317million pinch point programme, which aims to boost local economies by reducing congestion and delays at key locations.
Live traffic information is available on the Highways Agency website and mobile app, and drivers can also listen to traffic bulletins on local radio for updates.
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.