The UK government has approved a $750 million funding package for the Lower Thames Crossing, a major infrastructure project that aims to deliver the country’s largest road tunnel.
Connecting Tilbury in Essex with Gravesend in Kent, the project is expected to cost approximately $12.7 billion. It received planning consent in March 2024 after a protracted 16-year development phase that has already cost over $1.5 billion.
The 14.5-mile (23km) route includes a 2.6-mile twin-bore tunnel beneath the River Thames, which will become the longest road tunnel in the UK. The new road aims to ease traffic at the heavily congested Dartford Crossing and improve freight and transport links between ports in the southeast and key regions such as the Midlands and the North.
Billed as the UK’s greenest road project, the Lower Thames Crossing incorporates extensive environmental considerations. The initiative promises to deliver six times more green space than road surface, including one million new trees, two new public parks, a new community woodland, and seven green bridges—more than doubling the existing number in the UK.
Some of the project’s sustainability and innovation features include:
- Low-carbon footbridges: A new standard in footbridge design that eliminates concrete and reduces steel use to cut carbon emissions. These could be replicated across the national road network.
- Green bridges: Seven wildlife-friendly overpasses, including what will be Europe’s widest green bridge, connecting habitats and allowing safe passage for both people and wildlife.
- Pre-fabricated bridges: Constructed offsite using low-carbon methods, these bridges will reduce installation time, traffic disruption, and environmental impact.
- Landscape integration: Approximately 80% of the route will either run through tunnels or be hidden by landscaped embankments, preserving the countryside’s natural aesthetic.
- Low-impact gantries: Designed to use significantly less concrete and steel, these structures aim to minimise visual and environmental impact without compromising strength.
The Lower Thames Crossing is positioned as a key component of the UK’s long-term infrastructure strategy—enhancing connectivity, supporting economic growth, and setting a new benchmark in low-carbon road construction.