Designing and building the Lower Thames Crossing

Lower Thames Crossing - Design and build

It’s vital to get the design, construction and operation of the Lower Thames Crossing right to maximise its benefits and minimise its impacts.

The Lower Thames Crossing has been classified as a Nationally Significant Infrastructure Project, which means it will be developed in phases:

  • Design
  • Permission
  • Build
  • Operation

We will use construction techniques that minimise disruption. This includes the bored tunnel method, which will minimise impacts on the riverside marshes and riverbed, and offsite construction, which enables faster progress and use of the river for transporting materials.

How do we develop a new road scheme and how can you get involved?

The journey to the Lower Thames Crossing

Opening - 2027/2028*

The Lower Thames Crossing opens to traffic.

*We are using a date range of 2027 to 2028 to account for the natural uncertainty in developing a project of this size and scale. As we gather more information from consultation, our ground investigations and engagement with the supply chain, we will gain more certainty.

The Secretary of State then has three months to issue a decision. this will be followed by a public announcement.

If approved, construction could begin soon after.

The Planning Inspectorate will make a recommendation to the Secretary of State for Transport within three months of the end of the examination period.

You can register with the Planning Inspectorate as an interested party and make formal representations about the project. You will then be kept informed of progress and opportunities to be involved. The Planning Inspectorate will then examine our application.

Subject to the outcome of the consultation, we will make our submission to the Planning Inspectorate, which will include feedback from the consultation. This is called the Development Consent Order (DCO) application.

The Planning Inspectorate has 28 days to decide if the application meets the required standards to proceed, including whether our consultation has been adequate.

Highways England holds a design refinement consultation.


Highways England holds a supplementary consultation.

Highways England holds a second public consultation.

The Secretary of State for Transport announces the preferred route, a tunnel under the River Thames east of Garvesend and Tilbury (location C, route three with the Western Southern Link).

DfT asks Highways England to assess the economic, traffic, environmental and community impacts for locations A and C.

Location C is recommended as it offers far greater economic benefits and congestion relief.

A public consultation asks for feedback on proposals and location C, including 3 routes north of the river in Thurrock and Essex, and two south of the river in Kent.

The response to the consultation confirms the need for a new crossing between Kent, Thurrock and Essex. Option B is ruled out; the remaining two locations (A and C) are investigated further.

The DfT carries out a public consultation to ask for views on the location of the proposed crossing.

The DfT commissioned a study to assess the 3 remaining location options.

The government recognises the need for a new crossing by naming it a top 40 priority project in its National Infrastructure Plan.

Owing to increasing demand at the Dartford Crossing, the DfT looks at options for an additional crossing at five potential locations (A, B, C, D and E). The two furthest east are ruled out as they are too far from the existing crossing. Rail is also ruled out. 

Designing the crossing

The design for the Lower Thames Crossing aims to find the right balance between providing value for money, moving traffic effectively, and reducing the impact on local communities and the environment.

We have liaised closely with residents, community groups, businesses, local authorities and regulators over the past few years to develop our designs.

We have also been working with external agencies that are experts in this field, including the Design Council, to make sure our approach to design has been guided by the relevant standards and best practice.

Since presenting our detailed proposals in our 2018 statutory consultation, we have made considerable progress in developing the Lower Thames Crossing project. We have been refining the design, updating our traffic model and carrying out extensive environmental and geotechnical surveys, all while continuing to engage with our stakeholders.

In the summer of 2020, we held a design refinement consultation. The refinements described in the consultation have been informed by feedback received from our supplementary consultation, continued engagement with our stakeholders, ongoing design work and a greater understanding of technical constraints.


We plan to submit our Development Consent Order (DCO) application to the Planning Inspectorate in summer 2020. This will include feedback from the statutory and supplementary consultations.

The Planning Inspectorate will examine our application before making a recommendation to the Secretary of State. If it is approved, we will be awarded a DCO. This gives us permission to build.

The DCO process includes:

Pre-Application stage

We’re in this stage right now. This is when we present our scheme to you, the public, as well as relevant stakeholders like local authorities and regulated bodies such as the Environment Agency.

This does not mean the application is approved, it just means that the Planning Inspectorate has 28 days to decide whether we have submitted all relevant documentation to allow the application to move forward.

There are many documents that we’re required to include in our application, like an Environmental Statement, Consultation Report, and a Flood Risk Assessment. We plan to submit our application in summer 2020.

We will publicise that the application was accepted by the Planning Inspectorate to allow anyone to register as an interested party. This would then mean that they could attend public hearings and personally present their views and concerns.

Also during this stage, the Planning Inspectorate will appoint a panel of inspectors to serve as the examining authority, and a first meeting will be held to discuss procedural issues and the timetable for examination.

The examining authority will review our application within 6-months.

During the review, they will assess feedback from the public and stakeholders through written representations and public issue-specific or open hearings. Anyone who registered in the pre-examination phase can make a representation. This could include businesses, members of government, or individuals.

The examining authority will have 3 months to write a recommendation and submit it to government.

Government then has up to 3 months to make the final decision on whether to approve the DCO application and allow us to deliver the Lower Thames Crossing.

Provides a 6-week window for anyone with legal grounds to challenge the government’s decision through judicial review.

Building the crossing

Getting ready for construction

Before the main construction work can begin, we would need to acquire land and prepare the site. This would include:

  • diverting public rights of way and utilities
  • creating new habitats
  • carrying out flood avoidance measures
  • species relocation
  • removing vegetation as necessary
  • making any contaminated land safe
  • completing detailed surveys about the land and surrounding area
  • archaeology

We would build the new roads and tunnel in phases. This would be the most efficient way of working and would allow different elements of the project to be completed at the same time.

We would use construction techniques that minimise disruption. This would include the bored tunnel method, which reduces impacts on the riverside marshes and riverbed, and offsite construction, which enables faster progress and use of the river for transporting materials.

To maximise the amount of daylight hours during construction, we would plan to carry out most of the work between 7am and 7pm on weekdays (excluding bank holidays), and between 7am and 4pm on Saturdays. During the summer, to take advantage of the extended daylight hours and good weather conditions, we would undertake earthworks between 7am and 10pm. Our crews may work for up to an hour before and after to prepare and close the site.


We would liaise closely with highways teams from the local authorities in each affected area to identify the best working times for each site, so these may vary.

As with any project of this scale, some work would have to take place at night and on weekends. For example, where possible, we would work on existing roads overnight to reduce daytime disruption to drivers.

During construction, we would give affected residents, businesses and road users advance notice of planned works and provide regular updates on project progress.

It is likely to take around six years to build the tunnel and the road inside the tunnel. This project is an enormous undertaking using the most sophisticated tunnelling techniques in the world.

Operation of the tunnel boring machines would take place 24-hours-a-day throughout. This would be confined to the tunnel entrances and within the tunnel, and we would put in place noise and light mitigation.

The local ground conditions mean we expect a number of ground treatment measures would be required to strengthen specific areas of the ground or help control groundwater flows.

We would plan to build the new roads, junctions, bridges and underpasses at the same time as the tunnelling work. To enable the construction of the Lower Thames Crossing, where required, we would modify some of the existing side roads and infrastructure along the route.

The new road would connect the M2/A2 in Kent with the M25 south of junction 29 in Essex, crossing the A13 north of Chadwell St Mary. To connect with these existing roads, as well as the A1089, we would construct new junctions and would have to carry out some work on these roads as well. This would include improvements to the M2/A2 and M25.

We now have a greater understanding of our construction requirements and the potential routes construction vehicles would use to access the sites. We also have more information on how we can use and reuse material on our construction sites more efficiently, which would reduce the need for material deliveries and vehicle movements.

Where material has to be transported from elsewhere, we would expect most of this to be supplied from nearby locations. We are also exploring opportunities for alternative modes of transport, such as river barges, to carry materials and waste to and from our construction sites.

At the moment most of the materials would be transported to the construction sites by road, which would have some impact on the road network and its users. Since our statutory consultation, we have refined our routes to the construction sites, continued our assessments and made further design changes. This has given us a greater understanding of how we would be likely to use local roads and the Strategic Road Network.

Construction could affect local roads through temporary closures, diversions, traffic lights and/or lane restrictions. If the project receives consent and progresses to construction, we would provide advance notice of disruption, so people can look for alternative routes or travel arrangements.

A number of construction sites would be needed to build the Lower Thames Crossing. They have been positioned along the route based on our construction requirements and would provide access for our workforce and material deliveries.

At our five main sites, you would be likely to see temporary buildings and storage areas, including offices, space for equipment and materials, parking and staff welfare facilities.

Our secondary sites would be smaller and would typically include welfare facilities, materials and equipment.

Operating the crossing

The crossing

We are designing a road that will be fit for the future.

The road will have a maximum speed of 70mph and a control centre will use live traffic information from cameras along the route to monitor and alter these speeds as needed. Signs on the road and in the tunnel will let drivers know what the current speed limit is. They will also provide further information in the event on an emergency.

Our proposals contain traffic regulation measures that include prohibiting use by pedestrians, low-powered motorcycles, cyclists, horse riders and agricultural vehicles.

All standard-height vehicles that use the road, including coaches and HGVs, will be able to use the tunnel without restrictions.

Although walkers, cyclists and horse riders will not be able to use the Lower Thames Crossing, we have developed a detailed set of proposals for maintaining, improving and upgrading the nearby walking, cycling and horse-riding network.

It remains our proposal to apply a user charge for the Lower Thames Crossing, with a local resident discount scheme for those living in Thurrock and Gravesham.

The level of the charge and the charging regime would replicate the approach applied on the Dartford Crossing.

Therefore, the need for a Lower Thames Crossing charging consultation forum as suggested at statutory consultation is not considered necessary.