UPGRADE work to further enhance safety on the M4 and M5 around Bristol is set to start this month.

Motorists heading north from the south west are being warned that a six-mile section of motorway around the Almondsbury interchange is being upgraded, to further improve driver safety.

The work, on the M4 between junction 19 for Bristol and where it meets the M5 at the Almondsbury interchange, and on the M5 to junction 17 at Cribbs Causeway, includes:

Upgrading a 4-mile section of existing steel barrier to concrete in the central reservation of the M4 around Almondsbury interchange

Building three new emergency areas on the M5

Upgrading traffic signs to provide better information for drivers

Drainage work

Renewing lighting

Additional CCTV cameras

Concrete barriers are even stronger than metal ones and significantly reduce the risk of vehicles crossing over from one carriageway to another, improving safety and reducing the likelihood of incident-related congestion.

They are also virtually maintenance free and will last twice as long as normal metal barriers, with far less need for closures for routine repairs.

Paul Unwin, who is overseeing the upgrades for National Highways, said: ‘Safety is our number one priority. Upgrading these barriers will improve journeys and significantly reduce the risk of vehicles crossing over from one carriageway to another, improving safety and reducing the duration of incident-related congestion.

‘During the work we will do all we can to keep disruption to a minimum, but we expect that delays could be severe at peak times, so we are encouraging drivers to plan their journeys to avoid peak times if possible.

‘Getting it done at this time of year means the concrete can set just right and the contractors have a longer working window with more light.’

To minimise disruption while work to upgrade the barrier is carried out on the M4 and M5, three lanes will remain open to traffic in each direction.

However, one lane will be closed on each of the motorways, and the remaining lanes slightly narrowed, to help create a safe working area for the workforce.

The work will be closely coordinated with upcoming maintenance projects to refurbish two bridges at the junction 15 and 16 interchanges on the M5, which is expected to start this spring, sharing roadworks and resources to reduce disruption for drivers as much as possible.

National Highways is also providing an enhanced free recovery service to help any drivers who break down, or are involved in an incident, as quickly as possible and keep traffic moving for everyone else.

There will be a reduced speed limit of 50mph, temporary 24/7 roadworks CCTV monitoring and a free recovery service while work is being carried out.

On the M4, work to get the carriageways ready for narrow lanes is set to start on 27 February and is expected to last about a week.

Installation of the narrow lanes is planned to start on 7 March and will last for about two weeks.

These works will be undertaken overnight, with road closures and diversions in place. 

On the M5, narrow lanes preparations and temporary traffic management installation between junctions 16 and 17 are expected to start towards the end of March.

This will also be done overnight.

Main construction on these sections will start following the successful installation of the narrow lanes.

The overall work for both the M4 and M5 is expected to be completed during winter 2023.

During the main enhancements work there may be a need for overnight closures.

All associated planned closures will be listed on the travel updates/road closure section on the National Highways website.

This work is part of National Highways’ commitment to make England’s smart motorways even safer and improve confidence in them.

The M4/M5 Interchange is a dynamic hard shoulder section of motorway – this means the hard shoulder is used as a traffic lane at busy times.

As announced in the Government response to the Transport Select Committee inquiry into the rollout and safety of smart motorways, the conversion of DHS sections of motorway to all lane running has been paused while alternative ways to operate the dynamic hard shoulder are considered.