Diversions, closures and speed restrictions
We're trying to minimise road closures and keep traffic flowing as much as possible while the improvements are carried out. Stay up to date with diversions, road closures and current restrictions on this page.
While it won't always be possible to completely avoid some short-term delays and congestion, we have looked at lots of different scenarios and outcomes to keep open as many lanes as we can. We are working closely with local authorities to keep traffic moving as much as possible during construction.
What you can expect to see:
The A1, A421 and A428 will mainly remain open for the duration of the works.
There will be occasional overnight closures and full weekend closures, when we'll need to connect the new and existing roads, build bridges, and unload sizeable items of equipment or materials.
We're committed to being a good neighbour - so we're working hard with our contractors to plan and phase the construction, to really minimise impacts to all road users and the local community.
Current closures
Please remember that closures can change at short notice. You can check the latest information on our daily closures page or find live travel information on our Traffic England site. Our travel alerts give details of live incidents on our network.
Weekend closure of A428 - November 2024
Closure
To work safely, we'll close A428 between the B1040, St Ives Road and Caxton Gibbet roundabout at the following times:
- 6am on Saturday 30 November to 5am on Monday 2 December 2024
Diversion
Traffic will be diverted along the A428 towards St Neots. Traffic to continue northbound on B1040, St Ives Road and rejoin the A1198 south to Caxton Gibbet roundabout.
We estimate an additional journey time of 5 minutes.
Overnight closure of A421 between Renhold and Black Cat roundabout- 7 December to 8 December 2024
We're continuing to construct the new Roxton Road bridge over the A421.
With the beams now securely in place, the next step is to pour concrete for the bridge deck. This will create the foundation for the bridge’s new surface.
Closure
To work safely, we'll close the A421 in both directions between Renhold and the Black Cat roundabout from 6am on Saturday 7 to 5am on Sunday 8 December.
Diversion
Eastbound traffic diverted via the A603 at Cardington to A1 northbound at Sandy to Black Cat roundabout. Westbound traffic will use the same diversion route in reverse.
We estimate an additional journey time of 15 minutes.
View A421 diversion map.
Weekend closure of A428 from Tithe Farm roundabout to Caxton Gibbet roundabout - 13 December to 16 December 2024
As we continue building the new junction at Cambridge Road
We need to adjust the layout of the A428 (Cambridge Road) near to Tithe Farm roundabout while we build the new Cambridge Road junction.
This means traffic can continue to use the A428 safely during construction.
Closure
To work safely, we'll close the A428 between Tithe Farm roundabout and Caxton Gibbet roundabout from 9pm on Friday 13 to 5am on Monday 16 December.
Diversion
Traffic will be diverted along the A428 towards St Neots/A1 then continue north on A1 to Brampton Hut.
Return on A1 southbound to join A14 eastbound, leave A14 at A1198 Ermine Street and follow diversion signage along A1198 to Caxton Gibbet roundabout.
We estimate an additional journey time of 25 minutes.
View A428 Cambridge Road diversion map.
Give us your feedback
Use our A428 Black Cat to Caxton Gibbet improvements feedback tool to have your say.
This tool features an interactive map, allowing you to click on specific locations to leave targeted comments or provide general feedback.
ECHO is a one-way feedback tool, so if you'd like a response to your feedback you can email the project team at:info@a428.co.uk
Longer term closures
Temporary road layout at A1 / A421 Black Cat roundabout
In January 2024, we made a temporary switch to the road layout at the Black Cat roundabout as we began work to upgrade the junction. This temporary layout has allowed traffic to continue to pass through the roundabout smoothly - removing the need to close any part of the road permanently.
The current road layout will be in place until spring 2025.
Please be assured that we take your feedback extremely seriously and have been monitoring the area constantly since implementation. We monitor via live CCTV, as well as multiple daily visits to site at various times of the day, in daylight as well as in the dark.
Cycle, pedestrian and horse rider route closure, Caxton Gibbet
Cycle, pedestrian and horse rider route closure, Caxton Gibbet
As part of our work, we need to close the cycleway, pedestrian and horse rider route (73/17) just north of the existing roundabout.
While these works take place, cyclists, pedestrians, and horse riders will be directed along a diversion route, running eastward along the A1198 Ermine Street, avoiding our worksites and rejoining the road at Brockley Road.
We estimate the diversion will make journeys longer by:
- 5 minutes for cyclists
- 15 minutes for walkers
An upgraded route will open to cyclists, pedestrians, and horse riders in spring 2027.
Temporary closure of Cambridge Road (Eltisley)
Temporary closure of Cambridge Road (Eltisley) - 27 August 2024 to Spring 2025
As part of our work to upgrade Eltisley junction, we need to divert utilities and raise the level of the existing road.
To do this safely and efficiently, we'll need to close Cambridge Road for an extended period of time from Tuesday 27 August 2024.
We expect the work to be complete and the road reopened by spring 2025.
Diversion
Travelling from the A428
Traffic will be diverted along west of the A428 and then south onto the B1040 and east into Eltisley on the St Neots Road.
Travelling from The Green
Traffic will be diverted east out of Eltisley along St Neots Road, then north onto B1040 to the A428.
Permanent closure of A1 access from Chawston Lane
Permanent closure of A1 access from Chawston Lane - 30 August to Spring 2025
On Friday 30 August 2024, we'll permanently close the access to and from the A1 on Chawston Lane.
This will allow us speed up construction of the new Roxton Road link without multiple road closures.
The new link road is expected to be complete in spring 2025.
If you live on Chawston lane, you will still have access to your property. However, you will need to follow the dedicated diversion route.
Diversion
Travelling from Chawston Lane
Traffic will be diverted south down Roxton Road until it reaches the junction with Bedford Road. Road users will then head east towards the Black Cat roundabout or west towards Roxton village.
Travelling towards Chawston Lane
Traffic will be diverted north up Roxton Road until it reaches the junction with Chawston Lane.
Planning diversions, traffic management and speed limits
We've monitored traffic volumes at 24 different locations ahead of construction. We'll continue monitoring it throughout construction.
Highest safe speed
We've assessed that a 40mph temporary speed limit is necessary to protect road users and our workforce.
The temporary speed limit allows junctions to operate at their normal capacity. This means we'll need fewer full road closures.
Carriageway and slip road closures
We've planned our work to keep road closures, diversions and road layout changes to a minimum.
As far as possible, we'll only use closures for for essential works, like demolition or major phasing changes.
We'll use static narrowed lanes and temporary alignments to maximise working space. This will help us keep the number of full closures as low as possible. For example, we'll keep two lanes open on the A421 eastbound when we start construction.
Later in construction, we'll use some of the newly constructed slip roads to keep the traffic moving. We'll use slip roads and link roads to create a temporary ‘large gyratory’ at the Black Cat while we build the new A1 underpass.
How we choose diversion routes
We're committed to giving you safe and suitable diversions around closures. We'll only use diversion routes that can take the type and volume of traffic that's being diverted.
Diversion routes will stick to major A roads on our road network, minimising rat running on local roads. We'll agree diversion routes with the relevant local authorities.
We must follow the diversions set out in the development consent order (which is like our planning permission).
We'll reduce disruption by managing traffic with clear signs and advance warning.
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