A421 Full weekend closure

Reconstructed A421 central reservation 

From Monday 15 January, we will move the A421 eastbound traffic onto the reconstructed central reservation area on the approach to the Black Cat roundabout. The A421 westbound traffic will be restricted to one lane from the Black Cat to the end of our works area (approximately 1,200 meters or just over two minutes).  

The new alignment means we can build the new slip roads and new Roxton Road overbridge, with minimal disruption.

New road layout on the approach to the Black Cat roundabout

Through the approach and on the Black Cat roundabout, the layout of the lanes has changed to allow for the reduced number of lanes on the A421 westbound. The offside lane will take traffic on to A1 northbound and the nearside lane towards the A421 westbound and Roxton & Great Barford.

How will this affect me?

We are closing this stretch of the A421 westbound and eastbound to enable the transition of traffic to the new alignment, between Renhold and Black Cat roundabout from 9pm Friday 12 January to 5am Monday 15 January 2024. 

The diversion route will be clearly signed, as follows:

A421 eastbound: eastbound traffic diverted via the A603 at Cardington to A1 northbound at Sandy to Black Cat roundabout.  

A421 westbound: westbound traffic via the A1 Black Cat roundabout southbound to Sandy to the A603 to join the A421 westbound at Cardington.

Please plan your journey accordingly. Please also note that traffic approaching the closure location shortly before 9pm is likely to be subject to the diversion while the closure is put in place.

We apologise in advance for any inconvenience you may experience during the upcoming roadworks.

Reminder - What you will see

• 40mph speed restriction - will start approximately 1.2 miles on the approach to the Black Cat roundabout
• Speed cameras will be in operation to enforce the 40mph speed restriction
• Narrow lanes on A421 on approach to A1 Black Cat
• Temporary road realignment markings
• Workspace safety barriers and roadwork signs

How are we minimising disruption?

On the A421 eastbound, we've reconstructed the central reservation to make room for our work areas and keep two lanes of traffic moving during construction to minimise the impact on our customers.

By moving the alignment, we'll be able to build the new slip roads and overbridge for Roxton Road with minimal disruption.

Adapting our program of work has minimised phases and kept the number of full closures as low as possible to prevent continuous road closures.

The A1 will be kept open as much as possible. By building the slip road and link roads before the new A1 underpass is built and using them to create a temporary free-flowing roundabout (large gyratory), we'll be able to keep traffic moving on the A1 and A421 routes, reducing the number of full closures.

Please remember:

• Traffic approaching the closure location shortly before 9pm is likely to be subject to the diversion while the closure is put in place. 
• We always try to stick to timings; however, these closures may be amended due to poor weather or operational reasons. 
• You can get real-time traffic information via trafficengland.com.