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
The Lane, Wyboston - April 2025
UK Power Networks will be removing the overhead power cables, while we carry out surfacing works on the new Roxton Road.
To work safely, The Lane in Wyboston will be closed from 7am Tuesday 22 April until 5am Monday 28 April.
Diversion
We will divert traffic along The Lane and then south down Roxton Road until the junction with Bedford Road. Road users will then head east towards the Black Cat roundabout.
View The Lane diversion route map.
A421 eastbound overnight closure - April 2025
We will be repairing the parapets on the Roxton Road bridge. Parapets are the protective barriers or walls along the edges of a bridge to keep people and vehicles safe.
To work safely, the A421 eastbound carriageway between Black Cat roundabout and Renhold Interchange will be closed overnight from 8pm Thursday 24 April to 6am Friday 25 April 2025.
Diversion
We will divert traffic via the A603 at Cardington towards Sandy. Road users will then head north on the A1 to Black Cat roundabout.
Roxton Road weekend closures - May 2025
We’ll be preparing for the opening of the new Roxton Road and bridge. During the closure, we’ll surfacing the new road, install kerbs, and complete the tie-in between the new road and the existing network.
To work safely, Roxton Road will be closed at the following times:
- 7pm Friday 2 May to 6am Monday 5 May 2025
- 7pm Friday 9 May to 6am Monday 12 May 2025
Diversion
We will divert traffic along The Lane where they will join the A1 northbound and head towards Wyboston roundabout.
Pedestrians needing to use the footpath through the Roxton Road worksite will be safely escorted by a member of the team.
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
Eltisley junction opens to traffic - from April 2025
As part of the construction of the new A421 dual carriageway between the Black Cat roundabout and Caxton Gibbet,
We're making changes to to how drivers use the A428 at Eltisley:
- we'll remove the B1040 north junction at St Ives Road
- drivers will use two new roundabouts linked by a bridge crossing the new dual carriageway.
From 14 April 2025, we'll direct traffic on the A428 onto the new junction at Eltisley.
Following this we'll:
- remove the closed section of A428 carriageway
- build a new connection linking Cambridge Road (Eltisley) and the new southern roundabout.
We expect to reopen Cambridge Road (Eltisley) in summer 2025.
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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