Roads and rail; Active travel; and Parking

Sustainable and resilient surface connections play a key role in ensuring our passengers and colleagues can reach the airport and surrounding areas.

With expansion, Heathrow’s position as an integrated transport hub will grow, with new coach, rail, bus and cycle routes to the airport.

Roads and rail

Our objective as the airport grows is to ensure that the increasing number of passengers, colleagues and freight can be accommodated by improved surface connectivity in a way that does not affect local communities. To do this we need to manage surface access to limit both emissions and congestion, as well as relieving current issues on the local transport network – road and rail – and providing additional local connectivity.

As part of the expansion of Heathrow a number of roads around the airport, including the M25 and local roads, such as the A4 and A3044, and their associated junctions will need to be diverted. We will also introduce bus priority and cycling measures to ensure sustainable travel is a key part of these proposals.

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The M25 will be diverted offline with supporting collector distributor roads, that will help avoid weaving between junctions. Diverting offl ine means that the existing M25 will remain open while the diversion is built reducing effects on road users.

This will allow the new M25 carriageway and tunnel under the proposed runway to be constructed largely offl ine, up to 150m to the west of the existing M25.

The realigned motorway will be lowered by up to 4-4.5m into a tunnel under the proposed runway. The tunnel will be made up of four boxes – two for the new M25 mainline carriageways and one each for the northbound and southbound distributor roads.

Crossing a motorway with a runway or taxiway has been done successfully at other airports around the world such as Paris (Charles de Gaulle) and Atlanta.

M25 junctions

Changes will be made to surrounding junctions to maintain access to the M25 and connecting routes.

Junction 14 will have an enlarged roundabout to enable connection to the new A3044 north. A new roundabout at the eastern side of the existing Junction 14a will elevate it above the A3044, M25 and the proposed new river corridor.


The A3044 provides an important connection between West Drayton in the north and Staines to the south. The proposed diversion runs parallel to the M25 to the west, bypassing Poyle.

This option minimises property loss, effects on the Green Belt and avoids the construction of an extra tunnel beneath the new north west runway. The road will include a cycleway and we are also investigating the option of incorporating local widening for bus priority measures.


The A4 will be diverted from a new junction east of the Emirates Roundabout, northwards parallel to the M4 spur before crossing it just south of M4 Junction 4. It will pass Sipson to the north and then run north of Harmondsworth and be vital in connecting communities.

Between the Emirates roundabout and Holloway Lane junction it will be a dual link-road. To the east of Holloway Lane, it will be a wide single carriageway before re-joining the existing alignment of the A4 at a new junction just to the east of Brands Hill. The final road widths will be refined in due course to meet traffic capacity requirements, whilst including provision for bus and cycle priority measures.

The route of the A4 proposed includes a link road to the east of the M4 Spur to ensure it maintains its role as a local road rather than merging with the motorway.

Central Terminal Area (CTA) access

A new Southern Road Tunnel will be constructed to connect Beacon Road Junction roundabout to the south with the CTA. This will transform access to the airport from the south delivering significant benefits for local communities and businesses.

The importance of this connection has been highlighted by consultees and it will provide a new link for public transport (buses and coaches) and other vehicles. We are also investigating its suitability as a route for cyclists accessing the CTA from the south.

Southern Perimeter Road

The Southern Perimeter Road will be diverted to the north of the Southern Parkway and will link to the upgraded Stanwell Moor Junction. It will be widened, with new roundabouts constructed at Seaford Road and Stirling Road to replace existing junctions.

The Seaford Road roundabout will provide access to and from the Southern Parkway site. The Stirling Road roundabout will provide access to the consolidated cargo centre.

Stanwell Moor Junction

There will be a new multi-level roundabout junction on the A3113 at Stanwell Moor to enhance connectivity with the south of the airport. The option proposed has been chosen to minimise effects on property.


The existing Colnbrook branch line (‘railhead’) provides an important opportunity to move bulk construction materials to Heathrow and save thousands of HGV trips. The branch line is displaced by the new runway, but will be realigned to ensure that aviation fuel supply is maintained to the expanded airport, and a new rail head is proposed to optimise the sustainable transport of materials.
Other works proposed include additional connections onto the Great Western Mainline to allow for more flexibility on train paths from both east and west.

In addition, Heathrow is supporting and has safeguarded the on airport development needed for both Western and Southern Rail to directly serve the airport.

Active travel

Today, there are few facilities for walking and cycling around Heathrow. With over 19,000 of our colleagues today (or 26% of the Heathrow workforce) living within 5km of the airport, there is potential for increasing the proportion of our workforce choosing to walk or cycle to the airport in the future, with the associated health benefi ts this would bring. This forms an important part of our Surface Access Proposals and has informed the layout of our Preferred Masterplan.

Our aim is to better connect areas around Heathrow with the airport and employment locations around it. As part of this, we are proposing to create a ‘green loop’ which will support the wellbeing of our colleagues while helping the airport meet our sustainability objectives, including:

  • Creating cycle infrastructure which separates people on bikes from faster-moving traffic
  • Improving road crossings to ensure that major roads and junctions do not stop people cycling from nearby communities to the airport
  • Creating links to local communities, making short, local journeys much easier on foot and by bike

This network of active travel routes will be developed in consultation with local authorities. It will be integrated with existing walking and cycling routes, proposed schemes for improved walking and cycling routes being promoted by other organisations, our proposed green loop around the airport and diverted and improved highways close to the expanded airport. These improvements will not just serve the airport, they will signifi cantly enhance sustainable connections for local communities.

Active travel routes being investigated.

Feedback on active travel from previous consultations

Feedback received at our Airport Expansion Consultation One in 2018 suggested improving cycling facilities, routes and safety for our colleagues and our local communities, as well as the need for a good, pleasant walking environment around the airport.

We have responded to this feedback through our proposals for a Green Loop. This will benefit our local communities and our colleagues by making it easier to cycle and walk around the airport.

What is The Green Loop?

The Green Loop is a proposed, roughly 20km route around the airport made up of existing and proposed footpaths and cycleways. It can help to connect open spaces, communities and populations of wildlife.


Expansion provides the opportunity to transform how passengers and colleagues travel to and from the airport. Managing our car parking is an important part of how we plan to meet our pledge for no more airport related road traffic, the Airports NPS policy on modal shift and how we will also ensure that the airport’s impact on local air pollution does not delay the UK’s compliance with EU air quality limits.

Heathrow currently has a number of surface level car parks within and around the boundary of the airport which don’t make best use of the land and which require bus connections to terminals and other areas. Our commitment to sustainable growth means that we propose no significant increase in parking at the airport despite the scale of growth and we plan to minimise the use of land given over to parking by consolidating parking provision in new Southern and Northern Parkways.

In response to feedback received at Airport Expansion Consultation One, we have adjusted our proposals for parkways to enhance their design and minimise their effects on local communities. Construction costs and a high water table mean that we are not proposing below ground car parking.

More information on our consolidated parking proposals:

The Northern Parkway

The Northern Parkway will be close to the M4 and will have capacity for up to 24,000 spaces. It will serve the Central Terminal Area via direct shuttle services.

Both Parkways will be accessible by our enhanced pedestrian and cycle network and provide local communities with direct access to the airport and its facilities.

The Southern Parkway

The Southern Parkway will have capacity for up to 22,000 spaces. It will connect to the M25 and serve the Terminal 5 campus of the airport with direct shuttle services connecting straight into Terminal 5.

Both Parkways will be accessible by our enhanced pedestrian and cycle network and provide local communities with direct access to the airport and its facilities.

Terminal 4 multi-storey car park

We also propose to consolidate car parking around Terminal 4 with up to 6,500 spaces in a new multi-storey building to the south of the terminal.

The multi-storey building will accommodate car rental, authorised vehicles and taxi parking areas. Long stay passenger and colleague parking will be relocated to an enlarged parking area at the east end of the southern runway.

Feedback on parking from previous consultations

In response to feedback received at Airport Expansion Consultation One, we have adjusted our proposals for parkways to enhance their design and minimise their effects on local communities. Construction costs and a high water table mean that we are not proposing below ground car parking.

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