Barcelona is covering a road bridge with concrete that eats pollution

Image: BCQ.

Converting horrible bits of concrete transport infrastructure into green spaces has become a bit of a trend recently. In Hamburg, there's talk of turning a motorway into a park; then there are the dozens of attempts to piggyback on the success of New York's High Line by creating pedestrian walkways and parks.

But one Barcelona bridge is trying something a little different: it's keeping its cars, but introducing a host of sustainable green technologies to make it much, well, nicer.

The Sarajevo bridge is a member of what is surely the grimmest category of urban infrastructure: a road bridge over another road, to the north of the city centre. At the moment, it looks like this:

Under a plan commissioned by the city government and developed by architects BCQ, however, it's due to be transformed. It'll still be a road bridge, but its surface will be paved with pollution-eating "photocatalytic concrete". The pedestrian walkways will be widened so they can be used as plazas, while greenery-covered walls and a canopy will shield users from the noise of the six-lane road below. The bridge will also be entirely self-sufficient, with solar panels on the bridge powering LED lights.

Here's a mock-up of the new bridge as seen from the road below:

And a cross-section:

Click for a larger image.

There's no completion date for this project, which is one of a number of schemes intended to green currently unattractive bits of Barcelona. But it does have the backing of the city government, so unlike so projects that come with cool concept images attached it may actually happen.

We're most fascinated by the smog-sucking concrete, which uses the energy of the sun as it strikes the road to break down pollutants into neutral substances like water, oxygen and nitrates and sulfates; these stick to the surface, and are later washed away by rain.

This probably won't make much of a dent in the pollution produced by the roaring highway below, but every little helps. 

All images: BCQ Architects.

 
 
 
 

London Overground is experimenting with telling passengers which bits of the next train is busiest

There must be a better way than this: Tokyo during a 1972 rail strike. Image: Getty.

One of the most fun things to do, for those who enjoy claustrophobia and other people’s body odour, is to attempt to use a mass transit system at rush hour.

Travelling on the Central line at 6pm, for example, gives you all sorts of exciting opportunities to share a single square inch of floor space with a fellow passenger, all the while becoming intimately familiar with any personal hygiene problems they may happen to have. On some, particularly lovely days you might find you don’t even get to do this for ages, but first have to spend some exciting time enjoying it as a spectator sport, before actually being able to pack yourself into one unoccupied cranny of a train.

But fear not! Transport for London has come up with a plan: telling passengers which bits of the train have the most space on them.

Here’s the science part. Many trains include automatic train weighing systems, which do exactly what the name suggests: monitoring the downward force on any individual wheel axis in real time. The data thus gathered is used mostly to optimise the braking.

But it also serves as a good proxy for how crowded a particular carriage is. All TfL are doing here is translating that into real time information visible to passengers. It’s using the standard, traffic light colour system: green means go, yellow means “hmm, maybe not”, red means “oh dear god, no, no, no”. 

All this will, hopefully, encourage some to move down the platform to where the train is less crowded, spreading the load and reducing the number of passengers who find themselves becoming overly familiar with a total stranger’s armpit.

The system is not unique, even in London: trains on the Thameslink route, a heavy-rail line which runs north/south across town (past CityMetric towers!) has a similar system visible to passengers on board. And so far it’s only a trial, at a single station, Shoreditch High Street.

But you can, if you’re so minded, watch the information update every few seconds or so here.

Can’t see why you would, but I can’t see why I would either, and that hasn’t stopped me spending much of the day watching it, so, knock yourselves out.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

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