As part of our ongoing series about potholes, we take a closer look at the material used to pave the vast majority of Rhode Island's roads: asphalt.
It wasn't always this way.
Humans have used a bunch of different materials on their roads. The Romans used stone, early American settlers used logs. And if you think potholes are bad: "Horses urinate and defecate, and the wood absorbs the urine, and that made for an unpleasant odor," says Duke University professor Henry Petroski. He's author of "The Road Taken: The History and Future of America's Infrastructure."
Around the end of the 19th century, asphalt started to stick. In particular, that was thanks to lobbying efforts of a new sort of hobbyist: bicycle riders. Bike riding associations advocated for smoother roads that would let them ride farther and with less bone-shaking bumpiness. Later, after World War II, asphalt helped the U.S. drastically expand its roads and highway system.
Today, more than 90% of this country's roads are paved with asphalt. Accordingly, it's big business. Here in Rhode Island, Tom Miozzi runs an asphalt plant in North Kingstown. It's on this huge industrial lot, dotted with massive mounds of crushed rock. Bulldozers scoop the rock into these large metal funnels; the stones clatter down to a conveyor belt; the belt transports the rocks up into a chamber where they're dried out, then another chamber where they're rolled in tar at temperatures exceeding 400 degrees Fahrenheit.
From there, it's transferred into a truck, which will take the asphalt to its final destination: a private driveway, a playground blacktop, or, most likely, a pothole.
There are more sturdy road materials than asphalt -- concrete, for one. But concrete is more expensive up front, and the costs for roads are borne by local and state governments, whose budgets are generally pretty tight.
"It's that same old question," Petroski says. "Do you spend a lot of money upfront, or do you spend less money upfront and let a subsequent administration worry about its upkeep?"