Tunnel visions

Tunnels seem to be the centre of attention when it comes to infrastructure development in London at the moment.

Crossrail continues to snake its way through the belly of the capital and a safeguarded route for Crossrail 2 is set to gain legal protection later this year. The gigantic Thames Super Sewer will start burrowing its way underneath London in 2015 and earlier this month campaigners against east London’s tentatively proposed Silvertown Tunnel published research claiming that it will push pollution levels above EU limits. Finally, ambitious proposals to replace Hammersmith flyover with a tunnel gained widespread backing and publicity last month.

And now, what could potentially be the biggest tunnel of them all has been mooted by the mayor of London. The mayor’s Roads Task Force, an independent panel of senior industry personnel charged with developing a strategy for the future of the capital’s road network, has proposed a new 22-mile orbital tunnel that would form an inner ring-road underneath the city, loosely straddling the zone 1 boundary of the London Underground network.

The tunnel proposals, which are decidedly at concept stage, would link key transport nodes such as Elephant & Castle, Highbury & Islington, Battersea and Shepherd’s Bush and would also include an eastern spur to Hackney Wick. The tunnel would pass underneath the Thames at Wapping and Chelsea and, intriguingly, could result in the closure of Tower Bridge, (where width and loading constraints already impose a 20mph speed limit) to all traffic except buses and bikes.

At a mammoth cost of £30 billion, the new tunnel would be almost twice the cost of Crossrail and would be roughly in the same region as the government’s initial, rather fanciful estimates for HS2, which, considering current HS2 costs, does not bode well for future parsimony. However, in a funding strategy similar to that proposed for the Hammersmith flyunder, the mayor claims that a significant portion of these costs could be met by the commercial redevelopment of road space liberated from traffic.

The history

This isn’t the first time a mega tunnel has been proposed for London. Renowned planner Sir Patrick Abercrombie’s seminal 1943 and 1944 plans for London’s post-war reconstruction were heroic works of extraordinary vision, even though they did contain random nuggets of municipal madness.

Abercrombie proposed successive rings of radiating, orbital roads encircling central London. Heavily informed by the madcap functional compartmentalisation theories propagated by Le Corbusier and popular in the US urban planning at the time, cars, public transport and pedestrians would have been vertically separated and accommodated on either flyovers or, as under Hyde Park and the Thames, tunnels.

Mercifully the plans were never realised, although the acute dystopian grimness of the only parts that ever were, the Barbican’s Beech Street Tunnel and the so-called ‘A Ring’ of horrific London Wall, spitefully attest to what post-war London, though sadly not other British cities, was spared. As do the Westway and Blackwell Tunnel Approaches, the only realised segments of an even more ludicrous 1960s ‘Ringway’ scheme to submerge much of what the Luftwaffe had spared under cheerless belts of urban motorway.

London is also relatively unique among European capitals in not having an inner-city ring-road. Paris has the Peripherique, Berlin the Innenstadtring, Vienna the Ringstraße and Oslo the Ringveng.

The closest London gets to this is the notional boundary around the congestion charge zone encompassing routes like Park Lane and Euston Road. By any stretch of the imagination, the North and South Circulars, a disjointed and normally static necklace of juddering dual carriageways and quaint Victorian high streets whose full circuit can only be completed – incredibly – by boat, doesn’t really count.

Benefits

While a new orbital tunnel would clearly be a herculean and expensive undertaking, the potential environmental and urban benefits of plunging much of London’s traffic underground are of course huge. Transport for London predicts that by 2031, traffic congestion in the centre of London could surge by a whopping 60%. It is difficult to foresee how this rise could be accommodated on roads on which capacity is already often at breaking point.

Removing or at least significantly abating the highly corrosive sceptre of traffic from London’s future development could nullify what has consistently proved to be one of the biggest barriers to the improvement of public space in the capital. Every major pedestrianisation scheme in central London, including those at Leicester, Trafalgar and Parliament Squares has been vociferously opposed by the car lobby and is normally met by dire and inevitably unrealised predictions of traffic apocalypse elsewhere if implemented.

Dramatic reductions in traffic levels could lead to the more equitable distribution of space and priority between car and pedestrian that London desperately needs. Equally, a new orbital tunnel could invite a whole gamut of environmental benefits ranging from a re-landscaped public realm, more pedestrianisation and an expanded public transport network to cleaner air, reduced journey times and safer cycling. These liberating effects could force a fundamental psychological shift in our idea of what London is and how we use it.

Obstacles

But of course there would also be significant obstacles to this tunnel ever coming to fruition. Other similar schemes across the world, such as Boston’s infamous Big Dig which finished nine years late and on which costs spiralled by 200% saddling the city with debts until 2038, provide dire evidence of just how easy it is for mega infrastructure projects like this to go spectacularly wrong.

Moreover, in a complex, ancient and municipally intransigent city such as London whose attitude towards planning upheaval is so glacial that it took 17 years to pedestrianise Trafalgar Square, 22 years to build Heathrow Terminal 5 and, if it is ever built and opens to schedule, 25 years to build a third runway at Heathrow, the risk of profligacy and paralysis on big infrastructure projects is high.

And even if we set aside the toxic issues of cost and programme, is such a tunnel even required? Neil Bennett, partner at Farrells Architects, isn’t convinced. “With the growing pressure on London’s infrastructure, it’s right that we should look at all options for relieving transport hotspots but we should be sure to look at the complete issue, rather than ‘big bang’ solutions alone. Could we, for instance, network our systems better, to provide more options and more choice for travellers, rather than relying on single mode, high cost solutions?”

But even sterner criticism comes from another hugely credible source, leading UK transport expert and commentator Christan Wolmar. “It’s just another daft Boris fantasy that he comes up with now and then, like the cable car and the cycleways in the sky. He should focus on what is realistic and feasible for a mayor of London to do and not on what isn’t.”

Wolmar also predicts logistical mayhem if such a tunnel was ever constructed and isn’t convinced about the funding model either. “This tunnel would probably be built using the cut and cover approach yet there is absolutely no way the tunnel could be aligned with existing roads above which means infinite disruption to roads and properties. Also, it’s all very well and good to say that land would be freed for development to help pay for the tunnel but much of that land aligning existing roads will already have houses and properties along it. What happens to them?”

How then would Wolmar spend a hypothetical £30 billion to reduce congestion and improve public realm in London? “You have to have a programme looking ahead which Boris never does. It’s not enough for him to front Crossrail and previous projects like the Overground upgrade, what about Crossrail 2 and tube line extensions into south London?

“This endless focus on increasing road capacity is also misguided, the idea that there is endless demand is not true and whenever you do create extra road space it fills up very quickly. What we should be building is lots of small scale incremental improvements, it’s easy to think big but more complicated to think small. We should be investing in new orbital tram links and improving bus services and creating networks for walkers and cyclists as they’ve done in Seville. We have to change the nature of what we do in the city, you can’t build your way out of a congestion crisis, you reduce traffic demand by increasing and improving public transport supply.”

Cynics may point out that Wolmar’s impartiality might be slightly compromised by his potential candidacy for mayor of London in 2016. Nevertheless, his musings certainly ring true. With the single exception of the estuary airport and now his orbital tunnel, Johnson’s mayoralty has been characterised by the shameless promotion of the infrastructure improvements of others rather than the initiation of his own, as the continuing debacle of non-existent east London river crossings scandalously attests.

Moreover, such a major expansion of inner-city road capacity does feel like a regressive throwback to the bad old planning dogma of the 1960s. Today’s more sustainable urban development approach lies in promoting public transport and reducing, not increasing, reliance on the car.

Will the tunnel happen? Probably not. But it does represent the kind of big, visionary thinking that a city like London needs. If the idea is seriously progressed it is also likely to spark fierce debate and debate, regardless of its trigger or outcome, is never a bad thing.