Greenlight for £290 million improvements to M3 to support over 2,000 homes in Winchester
Source: gov.uk (2025-03-13)

Road scheme investment will save thousands of hours for commuters, tourists and freight every week.

- M3 J9 road scheme in South Hampshire approved for construction, as the government delivers another vital road project
- upgrades will shave off almost a third from the average peak journey time, support 2,000 new homes, improve safety and air quality and connect Southampton and Portsmouth ports for freight cargo
- £290 million set aside for the scheme as part of the government’s commitment to renew national infrastructure and drive growth as part of the Plan for Change
Winchester is set to see faster, safer journeys and 2,000 new homes, as ministers approve the M3 J9 scheme in South Hampshire, the government has announced today (13 March 2025).

Backed by £290 million of government funding, the road scheme will significantly speed up journey times, reducing the current bottleneck and saving commuters, businesses and tourists hundreds of hours each week.

Peak time journeys through the junction to the A272 into Winchester will be almost 30% faster. Between the M3 and A34, drivers will save more than 20% of their overall journey time during peak hours.

The scheme is also essential to building 2,000 new homes in Winchester, another milestone for this government’s Plan for Change (https://www.gov.uk/missions) to deliver 1.5 million homes over the next 5 years. To deliver this target, last month, the government also announced it was approving over £200 million for the A47 Thickthorn Junction in Norwich (https://www.gov.uk/government/news/ministers-approve-long-awaited-a47-road-scheme-to-support-over-40000-homes-and-30000-new-jobs), which will support 43,000 homes in Norwich.

To mark this significant landmark for drivers and businesses in Hampshire, the Transport Secretary visited the M3 J9 to mark the approval of the scheme and understand its impact on the local economy.

Transport Secretary, Heidi Alexander, said:

Anyone who uses this junction knows how frustrating it can be. But our £290 million investment will save thousands of hours for commuters, tourists and freight every week, unlocking the true potential of our ports to deliver economic growth.

We’re building rather than blocking so that we can get our economy growing. Approving these works, and the 2,000 homes it will support, is just another milestone on the way to delivering 1.5 million homes in this Parliament as part of our Plan for Change.

This government is investing in vital road schemes with huge economic benefits, and so far we’ve invested half a billion pounds for 6 schemes across England to renew our long neglected national infrastructure.

The junction is a key interchange for economic growth, connecting the ports of Southampton and Portsmouth to ship millions of tonnes of freight every year, providing a vital link for those travelling to the south coast and beyond.

Ministers have given the go ahead to the project as part of a wider drive to unblock vital transport infrastructure development.

Since entering office, the government has approved over £200 million for the A47 Thickthorn Junction and £90 million for the A130 Fairglen Interchange, the South East Aylesbury Link Road, the A350 Chippenham Bypass and the A647 scheme in Leeds (https://www.gov.uk/government/news/millions-to-see-faster-journeys-as-government-green-lights-90-million-for-4-essential-road-schemes-across-england). This is a total of over £580 million for schemes to get Britain moving. The government is also supporting the expansion of Heathrow Airport.

The new design will also improve safety by extending the southbound slip road onto the M3 so that traffic has more time to join the motorway.

The government is providing £290 million for the scheme, which is expected to generate millions more for the local economy of South Hampshire. It is part of the government’s Plan for Change to renew infrastructure and grow the economy.

With the aim to accelerate the delivery of infrastructure across the UK, the government is focused on improving the UK’s road network to increase economic growth.

Ross McNally, CEO and Executive Chair of Hampshire Chamber of Commerce said:

The M3 J9 go-ahead is welcome by all parts of the business community across South Hampshire and beyond. This will help to keep trade flowing at this important junction and support the jobs and investment in our high-value sectors across the region. The fact that the scheme will unlock new essential housing is great bonus.

Alastair Welch, Associated British Ports’ Regional Director for Southampton, said:

With 95% of UK trade passing through its seaports, good port connectivity is essential for growth. ABP’s Port of Southampton is a leading gateway for strategic sectors like car making. This welcome junction improvement addresses the single biggest bottleneck between the UK’s manufacturing heartland and Southampton – the UK’s gateway to the world and biggest deep sea export port – supporting jobs and prosperity in both areas.

The Junction 9 improvement and further work planned to upgrade the A326 will support continued UK access to global trade routes from the Solent for many years to come.

Leader of Hampshire County Council, Councillor Nick Adams-King, said:

This is a vitally important route both locally as well as nationally, connecting the manufacturing heartlands of the Midlands and North with the export ports in the South. I therefore welcome this investment in crucial infrastructure, which will help to improve journey reliability and times, boosting economic growth locally and supporting the development of new homes and communities nearby.

It will also help to ease traffic pressures in central Winchester, enabling us to improve the public spaces, walking, cycling and bus services in the city, as well as the air quality.

National Highways Chief Executive, Nick Harris, said:

We are delighted to see work begin on this much-anticipated project, which will bring substantial benefits to people using the junction every day.

Our improvements will provide a safer and more integrated road network that will boost economic growth, reduce congestion and noise, and create faster, more reliable journeys for all road users.

The project will also provide a host of environmental benefits, including more than 22 acres of chalk grassland, as well as new routes for walkers, cyclists and horse riders.

As well as faster journeys, drivers in Hampshire are also set to benefit from improved road surfaces, thanks to a recently announced £52.9 million uplift in highway maintenance funding for Hampshire. This is part of the government’s record £1.6 billion investment to fill the equivalent of 7 million potholes and repair roads across England (https://www.gov.uk/government/news/seven-million-more-potholes-to-be-filled-next-year-as-public-urged-to-report-roads-in-need-of-repair).

The scheme will see the number of lanes on the M3 increased from 3 to 4 through the junction as it passes under a wider gyratory, with free-flowing links between the M3 and the A34 in both directions.

Several new, safer routes for pedestrians, cyclists and horse riders will also be built, connecting Kings Worthy and Winnall and Long Walk and Easton Lane.

The area will also see benefits to the environment, as National Highways will be introducing 22.2 acres (equivalent to 13 football pitches) of ancient chalk grassland, a species-rich grass that grows on top of chalk and is said to be Europe’s equivalent of tropical rainforest. Since the Second World War, 80% of these grasslands have been lost.

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