The Lower Thames Crossing
A new tolled crossing of the Thames, 14 miles east of Dartford. Construction began in March 2026. Designed to relieve the M25 by taking up to a quarter of Dartford's traffic. Opening target: 2034, pushed back from 2032 in December 2025.
Status
Construction
Started
March 2026
Tunnels
Twin bored, ~4.25km
Capacity
~4 lanes equivalent
Approved
March 2025
Major build phase
2028 onwards
Expected opening
2034 (target)
Distance from Dartford
~14 miles east
Lower Thames Crossing timeline
The key dates from consent to opening, latest first-hand milestones verified against gov.uk and National Highways announcements.
- 25 Mar 2025Development consent grantedThe Secretary of State approves the A122 (Lower Thames Crossing) Development Consent Order after years of planning delays.
- Jun 2025£590m preliminary fundingGovernment commits £590m to prepare the site and start early works.
- Nov 2025£891m final trancheThe Budget allocates a further £891m, the final tranche of government support before private financing takes over.
- Dec 2025Private financing, opening slips to 2034Full private financing is confirmed, the cost is put at around £11bn, and the opening target moves from 2032 to 2034.
- Mar 2026Early construction beginsGround-investigation and infrastructure-preparation contracts get under way on site.
- 2028Major tunnelling phaseThe main construction and twin-tunnel boring phase is scheduled to start.
- 2034Opening targetThe crossing is due to open to traffic, taking up to a quarter of Dartford's flow.
Where it goes
The route runs from Shorne in Kent (near the M2 J1) up through twin bored tunnels under the Thames and emerges in South Ockendon, Essex (near M25 J29). Two new sections of dual carriageway link the tunnel mouths to the existing strategic road network. Total length is roughly 14 miles, of which 4.25km is tunnel.
Why it's being built
The Dartford Crossing carries roughly 150,000 vehicles per day against a design capacity of 135,000. Congestion has been the norm for two decades. The Lower Thames Crossing is intended to absorb 20-25% of Dartford's flow once open, restoring some spare capacity at the existing crossing and providing a redundancy route during incidents.
Will it be tolled?
National Highways has not published final pricing. The expectation is that it will be tolled to recover construction costs (the project is one of the most expensive UK road builds ever). It is likely the same Dart Charge or pre-pay infrastructure will handle payment, though that detail has not been confirmed.
What this means for current drivers
For the next several years, nothing changes. Dart Charge prices are set independently of the LTC. The Dartford Crossing will remain the only practical eastern route until the mid-2030s. The £25 resident pass and the pre-pay account remain the cheapest options for anyone who crosses regularly.
Funding milestones
The development consent order was granted by the Secretary of State on 25 March 2025. £590m of preliminary funding was approved in June 2025, followed by a further £891m in November 2025 to start the major works. In December 2025 the government confirmed the crossing would be delivered through full private financing, the project cost was put at around £11bn, and the completion target slipped from 2032 to 2034. Early ground-investigation and infrastructure-preparation contracts began in March 2026. The headline budget remains under public scrutiny.
Common questions
When will the Lower Thames Crossing open?+
The opening target is 2034. It was pushed back from 2032 in December 2025, when the government confirmed the crossing would be delivered through full private financing.
When did construction on the Lower Thames Crossing start?+
Early ground-investigation and infrastructure-preparation contracts began in March 2026. The major construction and tunnelling phase is scheduled from 2028 onwards.
When was the Lower Thames Crossing approved?+
The A122 (Lower Thames Crossing) Development Consent Order was granted by the Secretary of State on 25 March 2025, after years of planning delays.
How much does the Lower Thames Crossing cost to build?+
The project cost was put at around £11bn in December 2025. It is being delivered through full private financing, with government contributing the earlier funding tranches (£590m in June 2025 and £891m in November 2025).
Will the Lower Thames Crossing be tolled?+
National Highways has not published final pricing, but the crossing is expected to be tolled to recover its construction cost. The Dartford Crossing's £3.50 car charge is set independently and does not change when the Lower Thames Crossing opens.