On 25 March 2025 the government has given planning permission for National Highways’ A122 Lower Thames Crossing project. The decision, the recommendation made by the Examining Authority to the Secretary of State for Transport and the evidence considered by the Examining Authority in reaching its recommendation are publicly available on the
project pages of the National Infrastructure Planning website.
The most significant road project in a generation will drive growth – the priority in the government’s Plan for Change – by tackling long standing congestion at Dartford and improving connectivity between the south-east, the midlands and the north.
For more than 60 years the Dartford Crossing has stood as the only road crossing across the Thames east of London, making it one of the country’s most vital trade routes that connects some of the UK’s busiest ports to the rest of the country. Today, it is used by far more traffic than it was designed for and acts as a bottleneck that causes delays and diversions that holds back the country’s economy.
The Lower Thames Crossing is a 14.5 miles (23km) new A-road that will link the A2 in Kent with the A13 and M25 in Essex through the longest road tunnel in the UK. It will ease congestion at Dartford by almost doubling road capacity across the Thames east of London, and make tens of millions of journeys quicker, safer and more reliable every year.
The government is currently exploring private finance options for the project. Construction could start as early as 2026, with the new road expected to open in the early 2030s.
The National Highways project is the first in a new generation of projects that will accelerate the construction industry’s move to net zero by using fuels such as hydrogen to power its construction fleet and only using low-carbon concrete and steel.
The design of the new road was developed following a comprehensive programme of consultation with the local community and a range of organisations. Improvements made following feedback include future proofing it with three lanes in each direction along most of the route, reducing the impact on ancient woodland by 70%, and increasing the length of the tunnel to reduce impacts on local communities and the environment. Around 80% of the route now runs through a tunnel, cutting or embankment to blend it into the landscape and seven green bridges will blend the road into the landscape and provide safer crossing points for people and wildlife.
Before main construction gets underway, the project and its three delivery partners will work with local authorities, landowners, and stakeholders to refine aspects of the design to further reduce the impact of construction on the local community and environment, and embed new and emerging low carbon technologies and materials. Over the coming months they will also carry out archaeological, ecological, and topographical surveys, as well as further ground investigations to prepare the detailed design and construction plans.
