Johnson confirmed the schemes during a visit to Boston to examine the city’s network of underground roads.
The Mayor and Transport for London have considered more than 70 locations across the capital where the introduction of tunnels, fly-unders and decking could deliver benefits.
The five locations which have subsequently been identified as being suitable for further feasibility work by TfL are:
• A mini tunnel at the A13 in Barking Riverside – By creating a new tunnel for the A13, a huge amount of land could potentially be opened up for future development whilst reconnecting the Borough of Barking with the new Barking Riverside development, which is the location for just under 11,000 new homes
• Decking of the A3 in Tolworth – By decking over the A3, severance would be reduced and the area adjacent to the proposed Crossrail 2 station would be connected with the rest of the Borough, providing additional land for new homes
• A fly-under at the A316 at Chalkers Corner – A small flyunder would reduce severance and radically improve facilities for cyclists and pedestrians and remove a major pinch point for traffic along the A316
• A fly-under at the A4 in Hammersmith – By replacing the existing viaduct with a new tunnel, the town centre would be reconnected with the River Thames, creating new opportunities for development and open space
• Decking or a mini-tunnel at the A406 in New Southgate – By building over this junction on the North Circular, land would be unlocked for new homes and connect the area around the proposed Crossrail 2 station
Johnson, said: “Rebuilding some of our complex and aging road network underneath our city would not only provide additional capacity for traffic, but it would also unlock surface space and reduce the impact of noise and pollution.
“I am inspired by what the ambitious people of Boston have achieved here at the Big Dig, both in terms of reducing congestion and how they have dramatically improved the quality of life on the surface.
“In London we face similar challenges on our roads, but this could also be a fantastic opportunity to better shape our city and support economic growth.”
TfL will now work with local boroughs to progress these proposals further, including working up more detailed costs and possible funding options and an indicative programme of delivery if funding can be secured.
This further analysis will be presented to the Mayor in May.