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South west radial area study

The South West radial area incorporates the M4, M3 and A3, as well parts of the Great Western Railway and South Western Railway networks. It also includes the strategically important cross-Solent links with the Isle of Wight.

The study area covers the largest built-up area in the South East (south Hampshire) and international gateways at Heathrow Airport and the ports of Southampton and Portsmouth.

A map showing the South West radial area


  • Access to ports, particularly ABP Southampton (constraining its expansion) and challenges of accessing Portsmouth International Port
  • Sustainable surface access to Heathrow Airport from the South East area is poor
  • Congestion along the M4, M3 and A3, and South Western Main Line capacity constraints impacting on journey times, reliability, and ability to support new development
  • Journey times by rail to London from Portsmouth are notably longer than from Southampton


  • Potential for additional rail access to Heathrow from the south and west, plus mass rapid transit (MRT) solutions
  • The benefits that MRT could bring to some of the large conurbations (e.g. Thames Valley, south Hampshire) and how this might sit alongside other interventions that are planned or under construction
  • Improved rail capacity and reliability on the South Western Main Line through application of digital signalling alongside targeted infrastructure upgrades (e.g. Woking flyover)
  • Opportunities for demand management and other local sustainable transport and behaviour change interventions

Working in partnership

Partnership working is at the heart of our approach, making sure we capture invaluable insight and experience from stakeholders across the South East as we develop our investment priorities.

This area study is being led by a working group comprising senior officers from local transport authorities , local enterprise partnerships and other key partners including Network Rail and National Highways and protected landscapes.

The working group is supported by a stakeholder forum. This brings together a wide range of groups and organisations including transport operators, active travel campaigners, universities, environmental groups, local planning authorities, business groups and many more. 

South west radial steering group

ABP Southampton
Berkshire LEP
Bracknell Forest Council
Department for Transport
Enterprise M3 LEP
Hampshire County Council
Isle of Wight Council
National Highways
Network Rail
North Wessex Downs AONB
Portsmouth City Council
Reading Council
Royal Borough of Windsor & Maidenhead
Slough Council
Solent Transport
Southampton City Council
Surrey County Council
West Berkshire Council
Wokingham Borough Council

South west radial stakeholder forum

Arriva Southern Counties
Basingstoke and Deane Borough Council
Berkshire Local Transport Body
Bracknell Forest Council
Buses in Fleet
Campaign to Protect Rural England
Chartered Institute of Logistics and Transport
Confederation of British Industry
Confederation of Passenger Transport
Cross Country Arriva trains
East Hampshire District Council
Eastleigh Borough Council
England’s Economic Heartland
Elmbridge Borough Council
Enterprise M3 LEP
Epsom and Ewell Borough Council
Fareham Borough Council
Federation of Small Businesses
FirstBus Hants, Dorset & Berkshire
Friends of the Earth
Go South Coast
Gosport Borough Council
Govia Thameslink Railway
Guildford Borough Council
Great Western Railway
Hart District Council
Havant Borough Council
Heathrow Airport
Hillingdon London Borough Council
Homes England
Hounslow London Borough Council
Kingston London Borough Council
Logistics UK
Mole Valley District Council
Motorcycle Action Group

New Forest District Council
North Wessex Downs AONB
Portsmouth International Port
Rail Delivery Group
Rail Freight Group
Reading Council
Reading Buses
Richmond London Borough Council
Road Haulage Association
Royal Borough of Windsor and Maidenhead
Runnymede Borough Council
Rushmoor Borough Council
Slough Council
Solent LEP
South East Community Rail Partnership
South East England Councils
Southampton Airport
Spelthorne Borough Council
Stagecoach South
Surrey Heath Borough Council
Surrey Hills Borough Council
Sutton London Borough Council
South Western Railway
Test Valley Borough Council
Transport for London
Transport Action Network
Transport Focus
Transport Forum (TfSE)
Waverley Borough Council
West Berkshire Council
Western Gateway STB
Winchester City Council
Woking Borough Council
Wokingham Borough Council