NATIONAL Highways has announced the date when it will close the M4 near Bristol for the third and final time as part of work to replace the A432 Badminton Road bridge.
The latest closure will take place to allow eight steel beams, weighing 80 tonnes each, to be lifted into place over the motorway.
The motorway will shut in both directions between Junction 19 for the M32 at Hambrook and junction 18 for the A46, from 7pm on Friday October 10 to 6am on Monday October 13.
National Highways, which is responsible for the motorway and the bridge, warned people to expect “substantial disruption” and avoid the area if possible during the closure.
‘Last full weekend closure’ for bridge project
A spokesperson said: “The closure marks a key milestone for the scheme, which will see eight steel beams lifted into place across the motorway, marking the last full weekend closure of the M4 for this scheme and the final major stage of reconstruction.
“Once the beams have been lifted into place, the remainder of the new bridge will be constructed with minimal disruption to the motorway below and will be open to the public in early 2026.”
Each beam will span the eight lanes of motorway and embankment either side.
The bridge will be 46.5m (153ft) long and 20m (66ft) wide – 4m wider than the old bridge – with wider lanes and pavements “to meet today’s safety standards”.
It will have higher barriers than the old bridge, which was demolished earlier this year.
National Highways route manager Sean Walsh said: “The beam lift is a huge milestone in the construction of the new bridge, but we appreciate that any road closures can be frustrating for people.
“We need to fully close the M4 because we’ll be lifting eight 80-tonne steel beams into place, and it’s vital that we keep those doing the work and motorists safe.
“Once complete, the new bridge will help reconnect drivers, businesses and the local communities that have been impacted by the closure.”
Official diversion
During the closure an official diversion will be in place, with drivers signposted to use the M32, A4174 ring road, A420 and A46 past Hambrook, Downend, Emersons Green, Warmley, Wick and Dyrham.
It is the same diversion that was in place for the previous closures in October last year, when trenches were dug across the motorway to relay pipes and cables, and March this year, when the old bridge was demolished.
Many drivers avoided the official diversion during those closures but there were also long queues on alternative routes, including Westerleigh Road between Emersons Green and Tormarton, and roads through Pucklechurch.
National Highways said: “With 3,000 to 4,000 vehicles using this section of the M4 every hour during peak weekend periods, the closure is likely to cause substantial disruption, and drivers are advised, where possible, to avoid the area and plan their journeys for alternative times.
“National Highways thanks people for their patience while carrying out this significant construction work, which will bring smoother, more reliable, and safer journeys for road users.”
The old bridge, which used to carry thousands of cars a day over the motorway on the A432 Badminton Road, between Downend and Yate, was closed in July 2023 after “structural failures” were found.
The new bridge is expected to cost around £20 million, with beams would be made from low-maintenance ‘weathering steel’, which has a specially-formulated layer of stable rust that seals off the rest of the metal from the elements.
It will not have moving parts such as bearings and joints that need to be replaced, as the whole structure is designed to expand and contract as temperatures change.