Silvertown Tunnel Cuts East London Delays – But Critics Say Tolls, Not Capacity, Are Driving the Gains

TfL’s first full-year assessment points to faster journeys, fewer Blackwall Tunnel closures and a major rise in bus use, although campaigners argue the £2.2bn scheme has displaced traffic and that it is still too early to declare success.

The Silvertown Tunnel has delivered significant reductions in congestion during its first year of operation, according to new monitoring data published by Transport for London.

The £2.2 billion, 1.4km road tunnel opened in April 2025, creating a new link between Silvertown and the Greenwich Peninsula and providing an alternative to the heavily congested Blackwall Tunnel.

TfL says the scheme has largely achieved its early objectives, with journey times improving across several key approaches, fewer disruptive incidents involving over-height vehicles and a substantial increase in the number of passengers crossing the Thames by bus.

However, opponents maintain that the apparent improvement is primarily the result of tolls suppressing traffic rather than the additional road capacity created by the tunnel.

Journey Times Fall Sharply

TfL’s 12-month monitoring report shows some of the strongest improvements around the northern approach to the Blackwall Tunnel.

Average northbound journey times between Sun in the Sands and the Blackwall Tunnel were:

• 58% quicker during the morning peak

• 47% quicker during the evening peak

TfL also reported that morning journeys on parts of the corridor were up to 126% faster, while southbound trips between Bow Roundabout and the Blackwall Tunnel improved by around 70%.

Weekday northbound traffic on the A12 fell by approximately 2%, while the number of over-height vehicle incidents at the Blackwall Tunnel dropped by 23%.

Before the Silvertown Tunnel opened, the Blackwall crossing was forced to close hundreds of times each year, often because HGVs became stuck inside the older tunnel.

No Increase in Cross-River Traffic

One of the most closely watched concerns before opening was whether the additional road capacity would generate more traffic.

TfL’s report indicates that this has not happened so far.

Combined traffic across the Silvertown and Blackwall crossings remains below pre-opening levels, with no overall increase in weekday vehicle journeys across the Thames in east London.

Air quality monitoring also recorded a 17% reduction in average nitrogen dioxide concentrations compared with the previous year, although TfL acknowledged that pollution levels had already been falling across the area over the preceding five years.

Bus Use Surges

The most striking behavioural change has been the increase in bus travel.

More than 11% of all journeys through the two tunnels are now made by bus, representing a 290% increase compared with the period before Silvertown opened.

TfL says more than 10,000 bus journeys now cross the Thames each day on routes 108, 129 and Superloop route SL4.

Free travel was initially offered on bus services using the Silvertown and Blackwall tunnels, although that concession ended on 26 May 2026.

A free cycle shuttle also operated through the tunnel, attracting between 100 and 130 weekday users during the warmer months of 2025, with demand falling significantly during winter.

Alex Williams, TfL’s Chief Customer and Strategy Officer, said the figures demonstrated that improved river crossings and bus priority were encouraging more people to choose public transport.

Pressure Shifts Elsewhere

Not every part of the wider network has benefited.

Journey times through the Rotherhithe Tunnel increased, with weekday traffic rising by around 3%. TfL attributed some of the disruption to technical problems affecting operating systems.

Demand for the Woolwich Ferry also remained above pre-Silvertown levels, although its reliability was similarly affected by operational and technical issues.

Opponents argue these trends suggest congestion has been redistributed rather than removed.

The Greenwich Society, which campaigned against the scheme, said motorists had been pushed towards toll-free alternatives including the Woolwich Ferry, Tower Bridge and the Rotherhithe Tunnel.

The Toll Debate

Drivers using either the Silvertown or Blackwall Tunnel can pay up to £4 per crossing during peak periods.

TfL says the revenue supports traffic management, operating costs and repayment of the private finance arrangement used to deliver the tunnel.

The organisation had previously estimated that repayments would average about £100 million a year, although the cost recorded during the most recent financial year was approximately £67 million.

The Stop the Silvertown Tunnel Coalition remains highly critical of the project, describing it as a poor use of public money.

The group argues that tolling the Blackwall Tunnel alone would have reduced traffic while generating substantial revenue that could instead have been invested in public transport, cycling and walking infrastructure.

It also maintains that lower traffic levels prove the charges, rather than the new tunnel, are responsible for the improvement in journey times.

Mayor Hails Early Success

London Mayor Sir Sadiq Khan said the first-year figures showed the project was cutting delays while encouraging more sustainable travel.

He highlighted the reduced congestion around the Blackwall Tunnel as particularly important for businesses, freight operators and residents in east London.

Yet with only 12 months of data available, the debate is unlikely to end soon.

The initial figures provide TfL with evidence that the tunnel is improving reliability and reducing disruption, but the longer-term questions around traffic displacement, air quality, tolling and value for money will require several more years of monitoring before any definitive judgement can be made.