Design for Living: New designs for flexible streets

The CRA roading system being exhibited in Toronto.

In often-flooded, electrically powered and denser cities, what’s the future for our streets? A German company called Magment is trying to develop a remote energy transfer system for electric vehicles. Pads made from recycled materials and embedded in roads, to charge your EV as you drive.

Good for them. Maybe it will work. But even Magment itself says it will probably be horrendously expensive.

In America’s hottest city, Phoenix, Arizona, they’re painting a “sunscreen” on the roads so they reflect heat instead of storing it. They’re trying to reduce the amount of heat slow-released during the night, because it keeps the city too hot. The only problem: the reflected heat makes the days even hotter.

There’s a better answer, it’s not expensive and it creates a better environment. Plant lots of trees.

There are many other initiatives. Streets are public spaces, so the question is: how do we get the most from them? The Italian firm Carlo Ratti Associati (CRA) has developed a “Dynamic Street” with a “modular and reconfigurable paving system” made of hexagonal blocks of wood. Each paver has a hole in the middle: a socket for plug-and-play elements like bollards, a basketball hoop, whatever you can imagine.

The pavers might form a road for cars during the morning commute, then be re-configured as a kids’ playground and end the night as a party zone. You could trial a cycleway at almost no cost. You could change the ratios of space given to cars, walking, cycling, playing and hanging out, every day or every few years, however you perceive the need changing over time.

Changing the configuration of the pavers can be done “within hours or even minutes”, without digging up the road and with a minimum of other disruption to street users.

When the system was put on show in Canada, visitors were invited to use a “digital reconfigurator” – software on a tablet – to create their own street designs. Part of the appeal is to the imagination: you’re invited dream up new uses for the streets where you live.

Streets as safe, fun places to be. But we need more. Streets also need to be better at capturing, storing and channelling floodwater. Trees, berms and planted water sinks called swales are part of the answer. The street surface can help too.

CRA made its prototype out of wood, to keep the cost low and flexibility high, but the wood is porous. The idea was inspired by hexagonal concrete pavers installed by the French group IFSTTAR in the city of Nantes. They too are porous.

Rainwater is collected in aggregate beds underneath them and then either reused or allowed to soak into the ground. The pavers are also resistant to skidding and produce less tyre noise, and the aggregate itself is recycled.

As with the CRA system, the concrete pavers can easily be assembled and reassembled, using a tool built for the purpose.

And porous concrete pavers aren’t the last word, either. A Dutch company called CirculinQ, formerly PlasticRoad, has created a modular system that does much the same thing using recycled plastic blocks. Hollow chambers capture the water and can also carry utility cables.

We’re used to thinking of streets as expensive, permanent and unfriendly to climate action. None of that has to be true.