A46 Kenilworth bypass box structure phases of work

What we are doing

The A46 is a major highway that connects Coventry, Kenilworth and Leamington Spa to the M40. We constructed a box structure to take the new HS2 line under the A46 in Kenilworth, which was  built offline adjacent to the carriageway.

The box structure was moved into place using a “box push” technique across the existing carriageway in spring 2025.​ This construction method reduced the impact on road users and our workforce by working away from the carriageway and only installing traffic management on the A46 when it was essential.

The structure weighed approximately 15,000 tonnes and was made up of 4,300 cubic metres of concrete and 120 concrete beams.

Lane closures on the north and southbound carriageways with a speed restriction of 50mph remain in place.

Overnight closures of A46 to complete vehicle safety system and central reservation

To ensure the safety of our workforce, we will be closing a section of the A46 from the Stivichall Interchange (Festival Island) to the Thickthorn Island (A452 for Leamington and Kenilworth) overnight on the evenings of:

• 8pm to 6am Saturday 2 and on Sunday 3 August
• 8pm to 6am Saturday 16 and on Sunday 17 August

We will hold a date in late September, as a contingency in the event of a delay to the planned work.

We will complete the final vehicle safety system and central reservation, then remove all the traffic management ready to reopen the A46.

We continue to work with Warwickshire County Council who also have works on the A46.  Working in this way helps to reduce the overall impact on the travelling public.

For more information on Warwickshire County Council works, please visit https://www.warwickshire.gov.uk/major-transport-construction-projects/a46-stoneleigh-junction.

Full closure of A46 to complete ‘box push’ (completed)

To ensure the safety of our workforce, we closed a section of the A46 from the Stivichall Interchange (Festival Island) to the Thickthorn Island (A452 for Leamington and Kenilworth) for 18 days.

During this full closure we:

• Removed the existing road surface and embankment where the bridge is located and slid the A46 Overbridge into position. Once the bridge was installed, we  completed drainage works and installed a new road surface and markings.
• We assessed and inspected the new bridge and highway surfacing before re-opening the A46 Kenilworth Bypass to road users.

The A46 Kenilworth Bypass reopened to traffic on 30 April 2025– 30 hours ahead of schedule.

Previous phases of preparatory work (completed)

To facilitate the box push we needed to complete some preparatory works. The preparatory work was completed in three phases and included:

• Phase one: Vegetation clearance to provide access to working areas
• Phase two: Installation of CCTV and temporary vehicle restraint systems to monitor and support traffic flows, widening embankments next to the highway as well as realigning highway drainage
• Phase three: Carriageway drainage work

Phase one: Completed in April 2024

The vegetation clearance provided access to our working areas needed for further activity later in the programme.

We completed the vegetation clearance safely, by implementing a lane one restriction on a short section of the northbound carriageway of the A46 Kenilworth Bypass.

Phase two: Completed May – October 2024

Our second phase of preparatory work included:

• Installing temporary vehicle restraint systems to support the flow of traffic and ensuring the safety of our workforce
• Installing CCTV to monitor the flow of traffic
• Widening the embankment next to the carriageway
• Realigning drainage ahead of carriageway drainage work later in our programme

We installed a temporary vehicle restraint system (TVRS) creating a safe working area for our workforce, while we completed embankment widening works. These works required a single lane closure.

Phase three:  Completed February 2025

We completed drainage works alongside and under the existing carriageway to prepare for the bridge to be moved into place in spring 2025. To complete our works safely, temporary northbound and southbound lane restrictions were put in place. We also needed to implement two weekend closures.

We closed a section of the A46 between Festival Island (Coventry) and Thickthorn Island (Kenilworth) over the following weekends:

• 8pm Friday 7 February to 6am Monday 10 February
• 8pm Friday 14 February to 6am Monday 17 February

Additional supporting traffic management were in place in the local area to protect communities from through traffic and ease local traffic flows in the area.

Download information relating to these works

• Notice of Overnight Closure of A46 - August

Find out more about

• Warwickshire

If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email [email protected]