A panel, which representatives of Hammersmith & Fulham Council, Transport for London (TfL), engineers and the community, gathered for the debate, which was chaired BBC’s John Humphrys, himself a Hammersmth resident, at the Lyric Theatre.
The vast majority of the audience said it was in favour of having a flyunder, but the massive complexities surrounding the plans meant many doubted it would ever happen.
The panel consisted of council leader Steve Cowen, TfL’s planning managing director Richard de Cani, Tom Ryland from architect group West London Link and Hammersmith Society chairman, and engineer Martin Knights, from CH2M.
The panel said they were in favour of the flyunder scheme - which could also involve replacing a stretch of the A4 which currently runs through the area - but differences soon arose over various aspects.
Three tunnels are currently on the table, with one short one, a like-for-like replacement for the flyover, dismissed as pointless.
Other tunnels could run from Hogarth Roundabout to Barons Court and beyond. But TfL is looking at a ‘hybrid’ scheme which would see a 1.7km tunnel run from west of Town Hall to Barons Court, and cost £600-£700m in today’s money, but is not keen to pay for this.
Cllr Cowen said: “TfL and Boris Johnson are saying they don’t want to put any money in, they want it to be self-sufficient. We have to be self-financing.”
With reclaimed land being used to fund the project, concerns were raised at the number of properties required and the potential of a number of high-rise blocks. Mr Ryland suggested other alternatives to tower blocks would be popular.
TfL is also keen on seeing residents in the borough pay some extra money through rates for the project, arguing the flyunder will drive up property prices. But Cllr Cowen and several members of the audience voiced their concerns at this.
Other methods of funding, including business rates and a charge to use the new road, were also discussed.
Other bones of contention included linking the flyunder work with a new gyratory and bus garage plan, with Mr de Cani saying it should be looked at as a whole.
Some members of the audience suggested the flyunder may not be the answer.
One member said: “We know the flyover doesn’t work but we haven’t seen any other alternatives. We can’t keep building a temple to the car, there must be other choices.”
However, Mr de Cani said the flyunder would not increase car capacity, but rather remove it underground. Mr Knights said the technology will be available to clean fumes from a tunnel before it escapes into the atmosphere, making it a greener solution too.
He also pointed to other major cities across the globe who have carried out similar projects, saying: “This is not a new idea, it can be seen around the world. Technically, we can do this.”
Afterwards, members of the audience said there was a very long and complicated road to go down if the flyunder is ever realised.
The meeting was organised by HammersmithLondon BID and West London Link and was part of the London Festival of Architecture.