Transport for London is working up plans for a £30bn underground ring road to run for 22 miles under London’s streets.
The Inner Orbital Tunnel would have underground dual carriageways linking key routes, from the A40 Westway to the A12 in the east, and the A1 route north to the A2 running south.
The plans, revealed in London’s Evening Standard, would see Tower Bridge closed to all traffic except buses and bicycles, with the new tunnel creating two new crossings beneath the Thames.
Transport for London forecasts a 60 per cent surge in congestion in London’s central zone by 2031, while outer areas would suffer increases in congestion of 15 to 25 per cent.
The proposed route runs from Camden to Highbury, south under Whitechapel to cross the Thames at Wapping. It would head south of Elephant and Castle, under the Oval and Battersea Park, and crosses the Thames again at Chelsea. From there it would go through Earls Court to link with the A40 near White City, then east to St John’s Wood and under Regent’s Park. A spur under Dalston and Hackney would connect the circuit to the A12.
Detailed plans and funding for the scheme are not in place as TfL seeks public feedback on the plans, for which Mr Johnson said there were “big arguments in favour” and “obviously arguments against”.
It was reported that some of the cost would be met by freeing up development sites worth billions of pounds that currently suffer from high levels of traffic such as around the Vauxhall interchange.
Isabel Dedring, deputy mayor for transport, told the Evening Standard: “We are at the very early stage in exploring the potential. Cities such as Paris, Oslo and Boston have undertaken these kinds of ambitious projects and have seen dramatic results.
“This is not about creating a motorway through the centre of London. It’s about freeing up capacity on the city surface, improving air quality, and reclaiming space for public parks, pedestrians and cyclists.”