Hammersmith Flyover in West London is one of the first examples of an elevated road using reinforced concrete. Designed by G Maunsell & Partners & built in 1960, it has carried the A4 into Central London through Hammersmith as well as dividing local opinion and acting as a physical barrier ever since.
However, there are plans to turn the 6 lane flyover into a ‘flyunder’, comprising a range of tunnel options from shallow cut and cover to deep bore. It potentially makes a 2.5 mile strip of land ripe for development and already carries the endorsement of the Mayor of London, describing the scheme as “brilliant”.
The first official artist’s impressions of how Hammersmith town centre could look if a ‘flyunder’ burrows beneath it have been released showing land formerly blighted by the trunk road replaced by new homes, offices and green space. A report, drawn up by West London Link – a consortium of local designers in association with Channel Tunnel engineers Halcrow — was commissioned by Hammersmith & Fulham Council amid growing concern about the lifespan of the current route, which is used by 90,000 vehicles a day.
Transport for London is ultimately responsible as the A4 is a strategic route in the capital. It is spending £60 million fixing the 620-metre concrete structure after corrosion was identified and claim the work will keep the flyover in use for decades. The shortest “flyunder” option would run under the current route of the flyover and would cost £218 million. The longest 2.5-mile route would run from west of the Hogarth roundabout to Earl’s Court Road and would be the longest road tunnel in London. The third possibility is a 2.2-mile tunnel ending in West Kensington. Both longer, deep bore versions would also require a junction halfway along, near Hammersmith Broadway, to allow local traffic to use the tunnel.
Around £1billion worth of former highway land could be freed up to help pay for the flyunder works, according to a feasibility study.
Cllr Nicholas Botterill, Hammersmith & Fulham Council Leader, said: “A flyunder would enable Hammersmith Berlin Wall to be torn down and reconnect our divided town centre with the river and make our once beautiful town centre an even more attractive place to live in, visit or do business.”