Forum Topic

Replace Hammersmith Flyover with Hammersmith Tunnel

It's good news that finally we are going to be able to move on local roads because Hammersmith Flyover is reopening. What hasn't been fully highlight on the news item on the front page of this site is that this is not the end of it. TfL have patched things up on this rickety old structure well passed its sellby date for the Olympics but there will be more closures once that is over.LBHF have come up with the brilliant suggestion of putting the traffic on this section underground and this idea doesn't deserve to be ignored. How key this road is has been shown by the recent disruption - ultimately the current flyover will have to be replaced. This will be expensive. A tunnel will be more so but when you add back the massive increase in land values over the route of the tunnel the chances are that the net cost will be less than an overground solution. And just think how it would transform Hammersmith!

Danny Kopech ● 4727d9 Comments

Tunnelling is now common in all major cities - yes, Boston but also Seattle, Barcelona, Lyons, Rome (the Eternal City) and in Madeira. The technology appears to have come on in leaps and bounds. A Hammersmith tunnel would reunite the severed halves of the town. Let's come together to convince TfL we need it.

Rosemary Pettit ● 4656d

Carol - the Hammersmith Gyratory often is effectively a car park but much of it is under the flyover and it would be hard to manage north south traffic without it.

Paul Corcoran ● 4673d

This is the story of the Boston Big Dig.  Is there any guarantee that this would not happen here?The Big Dig was the most expensive highway project in the U.S. and was plagued by escalating costs, scheduling overruns, leaks, design flaws, charges of poor execution and use of substandard materials, criminal arrests, and even four deaths. The project was started in 1991 and scheduled to be completed in 1998 at an estimated cost of $2.8 billion (in 1982 dollars, US$6.0 billion adjusted for inflation as of 2006). The project was not completed, however, until December 2007, at a cost of over $14.6 billion ($8.08 billion in 1982 dollars) as of 2006. The Boston Globe estimated that the project will ultimately cost $22 billion, including interest, and that it will not be paid off until 2038.

C.Mowat ● 4687d

I am sure this is going to be dismissed as a dumb idea but why do we need a flyover or a tunnel?  I believe currently under the flyover at Hammersmith Broadway it is basically a car park so would it not be possible to flatten the flyover and turn the road that the flyover currently goes over in that area into two way, controlled by traffic lights at either end?

Carol Burge ● 4692d

"LBHF have come up with the brilliant suggestion of putting the traffic on this section underground "Why's that a 'brilliant suggestion'? It's a return to the discredited idea that you should lock-in car dependency by building massive infrastructure in entirely unsuitable places." the chances are that the net cost will be less than an overground solution. "I seriously doubt this.  The point of the flyover is that it crosses roads (and railways), so you can't reclaim land value back from them without removing them (you could cover the railway between the Ark and the police station with a building, I suppose, but that's not nearly enough land to pay for it).Not only are the approaches to a tunnel far more intrusive and segregating than the current bridge but the tunnel would have to be extremely deep (read: expensive) to get under the four lines of railway and you'd presumably have to build junctions on the surface at each end further out to get onto the thing, which again have no monetizable payback.My preferred option is reducing the whole A4 to two lanes from Chiswick to Warwick Road as a surface boulevard, removing the M4 elevated section when that breaks down (probably within ten or fifteen years, too) and possibly putting a tram or at least express bus down the thing, and replacing the Hammersmith Gyratory with normal two-way roads.  Hammersmith (and Chiswick) shouldn't have to put up with 100,000+ cars per day forever because some idiots in the 50s thought London should look like Los Angeles, nor should the middle of the town be set out like a racetrack.

Tom Barry ● 4693d

The Big Dig in Boston looks like providing a strong argument for not building a tunnel in Hammersmith.

Danny Kopech ● 4694d

Leeds has a 'ditch' running through the centre - not a far cry from a tunnel. Pity the tunnellers didn't go a tunnel inthe first place

Stephen Hill ● 4726d

Boston, The Big Dig, see Wiki..... http://en.wikipedia.org/wiki/Big_Dig

Iain Muir ● 4726d

In principle a great idea but are there any comparable examples anywhere in the world of an overpass in a densely developed urban area being replaced with a tunnel?

Paul Corcoran ● 4727d