M3 junctions 9 to 14: safety barrier upgrade
Making further improvements to safety on this key link between London and the Solent
Smart motorway upgrade cancelled
On 15 April 2023, the Government announced that plans for new smart motorways would be cancelled in recognition of the lack of public confidence felt by drivers and cost pressures. This follows an announcement in January 2022 to pause the rollout of new all lane running (ALR) smart motorways yet to start construction.
Although the M3 J9-14 ALR upgrade has been cancelled, we’re continuing to invest in safe and reliable journeys by upgrading the central reservation barrier along this stretch from steel to concrete.
The Government and National Highways will continue to invest £900 million in further safety improvements and to give motorists clear advice when using existing smart motorways.
For more information please visit nationalhighways.co.uk/our-work/smart-motorways-evidence-stocktake
Project information
The M3 motorway is a key part of the strategic road network and provides a vital economic link from the Midlands (via the A34) and London to the major ports of Southampton and Portsmouth on the south coast (via the M27).
England continues to have some of the safest roads in the world and, compared to other roads, motorways remain the safest roads to travel on.
Although the M3 J9-14 smart motorway upgrade has been cancelled, we'll be carrying out other work including:
- upgrading the central reservation barrier with a new reinforced concrete barrier to further enhance safety
- installing new drainage infrastructure in the central reservation
- replacing central reservation lighting where applicable
Concrete barriers significantly reduce the risk of vehicles crossing over from one carriageway to another. They further improve safety by reducing the duration of incident-related congestion.
As they are virtually maintenance-free, lasting twice as long as the current ones, future requirements for closures for routine repairs will be greatly reduced.
They are part of National Highways’ ongoing work to improve safety, maintain traffic flow and offer road user assurance.
Visit our M3 junctions 9 to 14: smart motorway feedback tool to have your say. The tool includes an interactive map. You can click on a location to make a specific comment, or give us your 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: M3J9-14SmartMotorway@nationalhighways.co.uk
Documents
Environmental Assessment Report
Environmental Assessment Report - Appendix A Part 1
Environmental Assessment Report - Appendix A Part 2
Environmental Assessment Report - Appendix A Part 3
Environmental Assessment Report - Appendix B Part 1
Environmental Assessment Report - Appendix B Part 2
Environmental Assessment Report - Appendix B Part 3
Environmental Assessment Report - Appendix B Part 4
Environmental Assessment Report - Appendix B Part 5
Environmental Assessment Report - Appendix B Part 6
Environmental summary
Frequently asked questions
The section of steel barrier between junction 12 and 14 was installed around 1991 and the section through junction 9 to 12 was constructed in about 1995.
Steel barriers have a minimum design life of 20 years but can last much longer when not exposed to harsh weather conditions.
Concrete barriers are much stronger than metal ones and significantly reduce the risk of vehicles crossing over from one carriageway to another, improving safety and reducing the duration of incident-related congestion.
They are virtually maintenance free and will last twice as long as metal barriers, with far less need for closures for routine repairs.
We are sequencing our plans with other schemes in the area:
- M27 junctions 4 to 11 motorway upgrade
Work to upgrade the M27 between junctions 4 and 11 to an all lane running motorway is near completion. We are however holding regular meetings with the M27 project team to co-ordinate planned work and closures, minimising the impact on road users. It is expected, should there be a connection of the temporary traffic management for each project (around M3 junctions 13 and 14), there will not be an increase of additional delays. - M3 junction 9 improvements scheme
The M3 junction 9 improvements project is currently undergoing Development Consent Order planning process. The scheme isn’t due to start until late 2023/early 2024. We are holding regular meetings with the scheme to keep them updated with our project. These meetings will continue throughout the duration of the M3 9 to 14 safety barrier improvements project.
We’ve taken into account and thoroughly studied the environmental aspects of the central reservation upgrade. It has been concluded there will be no significant effects on the environment either during construction or once the central reservation upgrade work has finished.
One of the activities for the central reservation safety barrier improvements work is removing the unintended vegetation and shrubbery growth from within the central reservation.
When removing vegetation, we do so in a manner to eliminate risk to the harming of wildlife. The necessary checks will be undertaken prior to clearance to ensure that animals and birds are identified, and appropriate controls are implemented if required.
If your vehicle has a problem, or you get into trouble on a motorway with roadworks, stay calm and try to exit at the next junction or motorway service area. If you cannot leave the motorway, you should:
- Move over as far left as possible towards the verge
- Put your hazard lights on to warn other drivers and help our control room staff spot you on CCTV. Traffic passing through road works is monitored by CCTV 24/7
- If you are in the left-hand lane and it is safe to do so, exit the vehicle via the left-hand door. Wait behind the barrier if possible
- If you cannot exit the vehicle, do not feel it is safe to do so, or there is no other place of relative safety, remain in the vehicle. Keep your seat belt on and dial ‘999’
Whatever part of National Highways' network you’re driving on, we want you to stay safe and know what to do if anything goes wrong.
Check our Road Safety pages for information about what to do when you see a Red X and driving on motorways.
If you are unable to follow our breakdowns advice for any reason, have stopped in a live traffic lane or feel your life is in danger:
- Stay in your vehicle with your seatbelt(s) and hazard lights on
- Call National Highways on 0300 123 5000 (or 999 if it is an emergency)
- Tell the operator if you are disabled and/or a vulnerable motorist such as an older person or travelling alone
- Keep details of your breakdown provider with you. Your breakdown provider may give you additional instructions in the event of a breakdown.
The emergency services will alert the control room and they will close motorway lanes with Red X(s) and send other help if required, such as a Traffic Officer.
Always carry any medication you need with you and prepare for your journey in advance.
People who are unable to use the emergency roadside phones due to a hearing, speech or physical impairment can contact us via text on 0738 028 3600 for roadside assistance.
We also offer British Sign Language users the SignLive service for getting in touch with our customer contact centre.
Both of these services are available 24 hours a day, every day of the year.’
Find out more about what to do in the event of a breakdown on a UK motorway.
Related Road projects

Traffic information
Information about scheduled roadworks and events on our motorways and major roads.X
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