A432 Badminton Road bridge, crossing the M4
The A432 Badminton Road bridge crosses the M4 on the outskirts of Bristol. Investigations have revealed damage to the bridge which cannot be repaired long term or cost effectively.
Come and meet the team from South Glos Council and National Highways to find out more about our work to replace the A432 Badminton Road bridge over the M4.
Where we'll be:
- Friday 17 May, 4 to 7.45pm at Henfield Hall, Coalpit Heath, BS36 2TZ
- Monday 20 May 3.30 to 7.15pm at Downend Library, BS16 5TW
Latest updates
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20 May 2024
Update – May 2024
Thank you to everyone who came to see us at the recent drop-in events. We’ve added the details shared at these events under ‘Project Information’ below.
What’s been happening and what’s next
We’ve now completed our investigations to determine the connections points of the utility pipes and cables that run through the bridge.
We’re continuing to work with providers and other authorities to ensure these utilities are moved before we demolish the bridge. The utilities will be moved to run under the M4, and this work is due to start in the autumn this year. We’ll provide more information on how this will be completed soon.
At present, we’re on schedule to start demolition of the bridge towards the end of the year, subject to coordination with utility providers and other authorities.
The bridge will remain open to pedestrians and cyclists until demolition takes place.
You may notice a site compound being set up near the bridge – this provides welfare facilities for our teams working on site, as well as a storage area for materials. Once work is complete, this compound will be removed and the area returned to its original condition.
We’ll also soon be putting ecological mitigation place so we can start clearing vegetation around the structure.
See our recent video-based update with South Gloucestershire Council on You Tube.
Reminder: as part of our ongoing inspection regime, an overnight closures of the M4 between J18 and J19 is planned for Thursday 13 June 2024. A diversion will be in place westbound via the A46 up to the A420 and back onto the M32 via the A4174. Eastbound in reverse.
During the day the M4 J18 to J19 will be open as usual.
Further overnight closures may be required before demolition of the structure.
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21 March 2024
Update - March 2024
Our ground investigation works have now been completed, photos below:
We'll carry out further investigations to determine utility connection points throughout March and April.
Ecological mitigation will be put in place before vegetation clearance around the structure begins.
At present, we are on schedule to begin trenching works below the M4 around mid-June, with an anticipated demolition date of September / October subject to coordination with utility providers and other authorities.
The bridge will remain open to pedestrians and cyclists until demolition takes place.
We held a video-based update with South Gloucestershire Council which can be found via this link.
As part of our ongoing inspection regime, overnight closures of the M4 between J18 and J19 are programmed for the following dates:
- Thursday 18 April 2024
- Thursday 16 May 2024
- Thursday 13 June 2024
A diversion will be in place via:
- Westbound via the A46 up to the A420 and back onto the M32 via the A4174
- Eastbound in reverse
During the day the M4 J18 to J19 will be open as usual.
Further overnight closures may be required before demolition of the structure.
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31 January 2024
Update - February 2024
We’re moving to the next phase of our work. This will involve vegetation clearance and the establishment of a site compound near the bridge. We’ll work mainly during daytime hours, please note our works may not always be visible. Some overnight works will also be needed, where possible we’ll complete noisiest activities before 11pm.
- 5 February to 29 March 2024 – vegetation clearance and site compound establishment near the bridge
- 14 and 15 February 2024 – overnight works near the bridge (these dates are subject to weather)
- 15 February 2024 – M4 J18 to J19 closed in both directions 8pm to 6am
For the closure of the M4, we would encourage all traffic to use the following diversions:
- Westbound - via the A46 up to the A420 and back onto the M32 via A4174
- Eastbound - in reverse
During the day the M4 J18 to J19 will be open as usual.
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01 December 2023
Work starts in the New Year
Following its closure in June, investigations have shown extensive cracking of the concrete and damage to the post-tensioning system, reducing the bridge’s ability to carry traffic without sustaining more damage. Neither strengthening nor refurbishment work would provide a long-term solution and would only extend the lifespan of the bridge for a limited time. Both these options would take a similar amount of time to complete as full replacement of the structure.
Demolition is planned for summer/autumn 2024 and plans are now underway for a new, 20-metre-wide bridge, that will reconnect South Gloucestershire communities and allow for more sustainable transport options to be considered. The project is expected to take about two years. Access across the current bridge will be maintained for cyclists and pedestrians before demolition, but due to timescale and cost it will not be possible to build a temporary bridge for motorists or pedestrians during construction of the new bridge.
From January 2024, local residents will see activity on site starting with ecological surveys and vegetation clearance to establish works compounds. Prior to demolition of the bridge, it will be necessary to divert services embedded in the structure, including a water main, high voltage cables, fibre optics cables, and a gas main.
We fully understand the disruption this closure causes, and we thank people for their patience as we move the project forward as quickly as possible.
A free shuttle bus service has been funded by National Highways. Bus operator Transpora have agreed the route from Yate Park & Ride, along the A432 to the bridge closure. It is then a short five-minute walk over the bridge to access additional bus services.
The free all-day service will operate every 30 minutes from 7am-7pm Monday to Friday.
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02 October 2023
Overnight closures
M4 J18 to J19 overnight closures – 8pm to 6am the following morning, subject to traffic flow:
- Tuesday 17 October 2023
- Thursday 16 November 2023
- Thursday 14 December 2023
- Thursday 11 January 2024
A diversion will be in place via:
- Westbound via the A46 up to the A420 and back onto the M32 via the A4174
- Eastbound in reverse
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05 September 2023
Free shuttle bus
A free shuttle bus service will be introduced Thursday 14 September 2023.
National Highways is funding the free service for communities affected by the closure of the bridge. Bus operator Transpora have agreed the route from Yate Park & Ride, along the A432 to the bridge closure. It is then a short five-minute walk over the bridge to access additional bus services.
The free all-day service will operate every 30 minutes from 7am-7pm Monday to Friday from September 14. This trial will initially run until the end of December.
Full details about the service can be found here.
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01 September 2023
Councillors invited to inspect bridge
On Wednesday 31/08/23 National Highways invited the co-leaders of South Gloucestershire Council, Councillors Claire Young and Ian Scott, to observe first-hand the ongoing investigation work at the A432 M4 overbridge and why we’ve taken the very unusual step to close the bridge.
During the visit we were able to show Councillors the technology we’re using to monitor the accelerating deterioration on the bridge deck and our engineers also took them under the bridge to inspect cracking to the underside of the deck. This gave an insight into conditions working near a live motorway and the need to work at night when traffic flows are lower. You can watch more about the visit.
Investigation work will continue until approximately the end of the first week in September. Work will then be paused on site to allow the outputs of the investigation to be analysed in detail in our offices and laboratories.
Options development work will take place in parallel with analysis where possible, and we anticipate a decision on next steps in December. The council will included in discussions and kept fully informed as matters progress. During this time, we will fund a shuttlebus to mitigate some of the disruption to public transport on the A432.
We understand people’s frustration at the disruption in the locality and we appreciate your patience as we work towards a solution.
Get more information on how this will affect local traffic.
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01 August 2023
Survey work continues
We’re continuing our survey work and will begin the next stage of our assessments on 7 August. We’re working overnight, Monday to Friday, when traffic flows on the M4 below the bridge are at their lowest. Our works will mean there will be some closures on the M4 (see below). There may be increased noise, where possible we’ll complete noisiest works before 11pm.
Please accept our apologies in advance for any disruption this will cause.
Access will be maintained for pedestrians and cyclists.
Traffic management
The bridge will be closed 24/7 to motorists until further notice.
- 7 to 14 August - M4 will be closed overnight between junctions 18 and 19 for safety reasons. The M4 will be open as usual during the day.
To reduce congestion and delays, drivers are advised to use the following diversions for the A432 Badminton Road closure:
- Northbound via the B4465 Westerleigh Road up to A46 and into Yate via A432
- Southbound in reverse
For the closure of the M4, we would encourage all traffic to use the following diversions:
- Westbound via the A46 up to the A420 and back onto the M32 via A4174
- Eastbound in reverse
We would advise all motorists to use the A420 and A46 for Yate from the Hicks Gate direction on the A4174, and motorway users to use the M4 junction 18 for Yate, rather than the M32 and A4174.
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12 July 2023
Bridge temporarily closed
The bridge was temporarily closed from 7pm 12 July 2023, to enable detailed structural investigations to continue.
Our recent survey work revealed accelerated deterioration and cracking to the southeast underside of the structure. Further investigations are beginning to reveal the full extent of the work required and the earliest a decision can be made regarding future restrictions is likely to be December 2023. We’re monitoring and investigating both the underside and top deck of the bridge, so work may not always be visible.
Until investigations and assessments of the bridge are completed, the bridge will remain closed to all motorists for safety reasons.
Access will be maintained for pedestrians and cyclists.
To reduce congestion and delays, drivers are advised to use the following diversions:
- Northbound via the B4465 Westerleigh Road up to A46 and into Yate via A432
- Southbound in reverse
National Highways is also encouraging all traffic to use the A420 and A46 for Yate from the Hicks Gate direction on the A4174, and motorway users to use the M4 junction 18 for Yate, rather than the M32 and A4174.
Thank you for your patience while this important safety work is carried out.
Project information
Constructed in 1966, the bridge is a concrete post tensioned structure, designed at a time when future maintenance was less of a consideration.
We manage the bridge via a series of regular routine investigations and inspections. In July 2023 we carried out planned detailed structural investigations.
This survey work revealed accelerated deterioration and cracking to the southeast underside of the structure.
The decision was made to close the bridge to traffic with access maintained for cyclists and pedestrians.
South Gloucestershire Council are supporting National Highways in managing traffic impact on their network and communicating with the wider community.
We’ve considered three options to either repair or replace the bridge:
- Do minimum
- Strengthening
- Replacement
From our findings, the recommendation was to replace the existing structure with an online replacement bridge. An online replacement bridge follows a similar alignment and footprint to the existing bridge, making the design and construction the quickest and most economically effective option for replacement. Before we demolish the existing bridge we need to remove multiple utilities from the bridge and bury them under the M4 motorway.
The benefits of a replacement bridge
There are many benefits of the online replacement bridge option:
- It’s quicker to deliver – the need for land purchase, planning requirements and consultations is reduced.
- Pedestrian and cycling facilities will be much improved, with wider shared footways and higher parapets.
- The bridge can be constructed within National Highways / South Gloucestershire Council owned land.
- Disruption to the A4174 and Cuckoo Lane can be minimised.
- There’s less impact on adjacent established woodland.
A typical scheme development and construction timeline can take 4 to 5 years. We’re accelerating this scheme and aim to deliver in a much shorter timeframe under the following provisional programme:
- Bridge design: December 2023 – ongoing
- Environmental surveys: December 2023 – February 2024
- Ground investigation: December 2023 – February 2024
- Utilities removal and culverting under the M4: Autumn 2024
- Demolition of existing bridge: Autumn 2024
- Construction of the new bridge: Autumn 2024 – early 2026
Why have you closed the bridge?
During the current structural inspection, accelerated deterioration and cracking to the southeast underside of the structure was identified. We have therefore made the decision to close the structure as this will limit any further damage whilst we undertake detailed investigations into the nature and extent of the defects and assess their impact on the structure.
How long will it take?
Following decision to demolish and replace the bridge, we’re working with other authorities and utility providers to undertake this work as soon as we are able. Design work has started on the new bridge and we’re currently planning to demolish the old bridge by the end of 2024, with a replacement ready for use in early 2026. There are many variables and other partners involved in this work and we’ll be able to provide more information on timings as work progresses.
Why will it take so long?
The structural investigations are detailed and specialist, and works are being undertaken by specialist contractors. The works involve identifying potential defects using digital scanning and then drilling into the structure to check the condition of the post-tensioning system using a range of techniques. We are currently working on the underside of the structure at night under lane closures on the M4 and are looking to accelerate the topside works, before assessing the data and looking at all available options for the future of the structure.
When did you first find cracking?
Many structures have cracks in them for much of their life – this is not unusual. The general approach is to monitor and manage the situation, much as you might monitor a crack in a ceiling. We employ a rigorous inspection regime that has identified sudden and accelerating deterioration. Over time the situation has worsened but nothing in previous inspections indicated any compromise to the structure.
Why did you not act sooner?
At various stages through the life of the structure it has been subjected to investigations into the causes of the cracking, none of these have raised concerns regarding the integrity of the structure.
Do you inspect bridges often enough?
Yes, we inspect in line with industry standards, with detailed inspections every six years, and general inspections every two years.
What type of bridge is this?
The bridge is a 3-span reinforced concrete post-tensioned structure. Post-tensioning is a technique used for reinforcing concrete structures and is a way of producing thinner more efficient structures with longer spans. Steel post-tensioning cables run through the bridge inside steel ducts. The ducts are positioned in forms prior to concrete being poured. Once the concrete has been poured and gained strength, the cables are pulled tight or tensioned, and anchored against the outer edges of the concrete. The ducts are then grouted to protect the steel tendons against corrosion and to help with the transfer of compressive forces to the structure.
Is it dangerous to the M4 below?
The full closure of the bridge and removing traffic from it will minimise the risk to the M4 below. In addition, we will inspect on a daily basis. If required we will close lanes on the M4 to ensure safety.
How much is this costing?
Until the investigation and assessment works are complete we are unable to say.
Why can’t I see any work going on?
Work is currently taking place overnight on the underside of the bridge, with lane closures in place on the M4 below. The work will become more visible when we start to work on the topside.
Can emergency services use the bridge?
We’re working really closely with the emergency services in the area to make sure they are aware of the situation. For the safety of those using the M4 below, emergency services will be unable to use the bridge. This is at the forefront of our minds and we’re doing everything we can to support the emergency services during this investigation and assessment work.
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Traffic information
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