12 July 2008

Ideas for a World-Class City, no. 8

Asphalt Alternatives

There are three problems with asphalt in urban areas:

1) Asphalt has poor reflectivity. It absorbs daytime heat and releases it back into the air. While this may have the benefit of inspiring new dance moves for barefoot people on driveways, it contributes to higher cooling costs and, in places like the Ohio Valley, the higher temperatures translate to worse air quality.

2) Asphalt is non-porous. There is nowhere for rainwater to go except storm drains.

3) Asphalt is a petrochemical product. Asphalt is way down on the list of reasons for high oil prices but any non-petro alternative is a welcome part of the overall attempt to reduce dependence on foreign oil and oil in general.

While looking for information about a related topic I found two companies that provide intriguing alternatives to asphalt paving.

TerraFirm Enterprises
Invisible Structures, Inc.

Both companies make a similar product which is basically a modular plastic grid that covers the ground. The spaces in the grid can be filled with grass or gravel. The result is a porous, reflective surface made out of recycled plastic and earth. ISI has a very good product information video on their site.

As I've opined before, parking lots are a poor use of land where real estate is at a premium (as in the urban core) but in the outlying areas and 'burbs this could be an excellent idea for lots, driveways and side streets.

A possible application downtown might as a replacement material for streets in the business district where traffic doesn't move fast. It's fiscally advantageous because the grid doesn't have to be resurfaced regularly like asphalt (no labor cost, no materials cost, no lane closings). And if the city is crazy enough it can even fill the grid with grass and have streets made of backyard.

Now that's nuts. But hey, why not? It's not like people have sentimentality for asphalt.

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