What Lies Beneath: Pavement Edition

Carl Monismith, Director of the UC Pavement Research Center, and Jim Signore, the center's Assistant Director. Photo by Casey Miner.

(San Francisco–Casey Miner, KALW News) If you’re driving right now, or riding a bus, trolley, taxicab or your bike after a long day at work, your mind might be on the traffic, or what to cook for dinner (or why won’t that guy turn off his blinker already?). But have you ever thought about what’s underneath your wheels? The actual road?

It’s the kind of thing we only really notice when it’s not working (ahem, potholes), but pavement is everywhere. The U.S. has four million miles of paved roads, and close to ten percent of them are in California. And as KALW learned, "Pavements are complicated. They’re not the easiest thing in the world to build...It may look simple, but (it) really is an engineered structure."

KALW visited the U.C. Pavement Research Center to get some answers about just what goes into making what’s beneath our feet.  For instance: How do you know if you've made a good batch of pavement? "When you mix asphalt and aggregate together and come out of mixer, it looks like maggots in the garbage can. It’s an indication that the mix is pretty good."

Hear the story at KALW News.