M3 junction 9 improvements

We’re proposing to change junction 9, so it has free-flowing links between the M3 and the A34 both northbound and southbound.

Start date 2023-24
End date Road Period 3 (2025-2030)
Cost £110 - £130 million

Latest updates

  • 11 November 2020

    Surveys continue while we plan for consultation

    Our surveyors have been continuing to work over the past few months collecting information about the local environment, and the plants and animals that are found there. This information is important, as it will form part of our application for a Development Consent Order (the special type of planning permission needed to build nationally significant infrastructure projects like this one). It also helps us plan what we would need to do to protect any endangered species found, should we get permission to construct the scheme.

    As well as continuing with our surveys, we’re also working hard to plan a coronavirus-compliant consultation on the revised scheme proposals. We expect to hold this early next year, giving people the chance to comment on the revised proposals. We will update this page with further information when the dates for the consultation are confirmed.

  • 16 June 2020

    Land surveys around junction 9

    From mid-June we’ll be doing surveys on the land around junction 9. We need to keep our environmental information up to date and ready for when we apply for consent to build the scheme. That involves resurveying key areas. By doing this we know what protected species are in the area and what we need to do to minimise the impact of our work on them.

    Most of our surveys will take place in June and July but we’ll continue to update our environmental information throughout the remainder of the year, which means we’ll need to do several more surveys later in the year. Some of these must take place at specific times, depending on the species we’re looking for.

  • 01 April 2020

    Further public consultations

    A full report on our 2019 design consultation will be available in spring 2020. We aim to go back out to public consultation with a further refined set of proposals later in 2020.

  • 19 March 2020

    Proposal review

    We consulted the public on our proposals for improving junction 9 of the M3 in summer 2019. The feedback received during that consultation showed there is widespread support for changes to the junction which will reduce congestion and improve traffic flow.

    Following feedback from our 2018 consultation, we made improvements on the A34/A33 northbound weaving lengths. In further feedback received in the 2019 summer consultation events, some people told us that they continued to be worried that weaving lengths northward of the new junction along the A34 were not long enough.

    We have taken that feedback into account, along with new information from additional traffic modelling, and are now reviewing our original proposals. By doing this we’re making sure our final designs are for an even better performing junction.

Project information


The M3 connects south Hampshire with London, the Midlands and the North. It is also part of a key freight route. Roughly 6,000 vehicles an hour go through junction 9 during peak periods and traffic is particularly heavy between the M3 and the A34, with frequent queues on the northbound off-slip of the M3 which are a safety risk. At the moment we reduce the queues by allocating more time on green at the traffic lights on the northbound off-slip of the M3 and the A34 link. This amended sequencing, in turn, causes lengthy queues on the A272 Spitfire Link and Easton Lane. Overall the junction creates a bottleneck and significant delays. 

The new proposed layout for the junction aims to: 

  • Improve safety by reducing queuing and delays 
  • Reduce congestion and improve journey times 
  • Reduce the number of people affected by noise and improve air quality 
  • Improve conditions for non-motorised users – a new cycle path would connect with National Cycle Network Route 23 which is severed by the current layout 
  • Support economic growth – improving road capacity which will help create jobs, improve business and support the building of new homes

The changes we’re proposing would reduce congestion at the junction and help make journey times more reliable. With less congestion there would also be fewer accidents and better air quality. 


Traffic information

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

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