"Our principal job is to make sure that people and goods can move through the city," says Roger Geller, bicycle coordinator for Portland, Ore. "If all the new residents coming into Portland drive at current rates, nobody is going to be moving."
Some of the burgeoning interest in pedal power is generational. Biking appeals to many of the nation's younger mayors, such as Anthony Foxx of Charlotte, N.C., the newly appointed head of the US Department of Transportation.
"There is a new class of mayors who understand urban systems better," says Shin-pei Tsay, who follows cities and transportation for the Carnegie Endowment for International Peace in New York. "They are asking what is the most efficient way to move people."
States are pushing alternative forms of transportation, too. In 2006, California passed a "sustainable communities" law that requires every metro area to come up with ways to reduce greenhouse gases related to travel. It is forcing cities to consider both more pedestrian and bicycle facilities.
"There will be way more investment in bikes than in the past," predicts Bill Fulton, vice president at Smart Growth America, a coalition of groups that advocate for less urban sprawl.
In some cases, biking is just part of the local ethos. Take Portland, probably America's premier cycling city. Bicycling magazine recently voted it – once again – the most "bike-friendly" city in America as part of a ranking it does every two years. Portland lost out last time around to Minneapolis.
According to the US Census Bureau, more than 6 percent of Portland's commuters (17,000 people) go to work on two wheels – 12 times the national average. Portland knows precisely how many of them ride each day over the Hawthorne Bridge, a main artery, since it installed a digital counter donated by a nonprofit group. Officials use the information to help plot bike routes and plan facilities.