With our roads in a sorry state, a cheaper, cleaner way of repairing them by recycling old asphalt is catching on in parts of California.
Recession is the mother of invention.
With transportation infrastructure in a sorry state in California—the proliferation of potholes in Los Angeles, for example, is incredible—more cities are turning to a method of repairing roads by recycling them. The cold in-place recycling process involves shaving off the top two to four inches of asphalt on a damaged road, pulverizing it and mixing it with additives, and then laying it back down and grading and compacting it. It's all done by a single train of machines and a road that's repaired this way can be used again the next day (a protective "overlay" is added a week later).
Conventional road repair, by contrast, involves removing six inches of asphalt, hauling it to the landfill, and replacing it with new asphalt. The process takes many days, is worse for the environment, and is more expensive.
In Gilroy, one of the California cities that's now using cold in-place recycling, a recent road repair project cost the city $120,000 instead of $200,000. TreeHugger points to a Metropolitan Transportation Commission report that says it emits 131,000 fewer pounds of CO2 per mile of road compared with conventional hot asphalt.
It's not an entirely new invention. It's been in use already in other parts of the United States and in Europe. But it looks like it's spreading now. Along with Gilroy, cities in the San Francisco Bay Area are getting involved.
It's a little crazy that this practice isn't just the norm given that it is, apparently, better by every measure. That's one silver lining of the recession: It's jolting cities out of sub-optimal standard practices that they wouldn't question if they had more money.