Kim Gallagher has a plan for America's "blue highways," the thousands of miles of dusty, old single-lane heritage routes that wend desolately through the countryside: turn them green. Superseded by high-speed interstates, many of these narrow byways have been long forgotten, along with the faded small towns they connect, says Gallagher, a project manager for the Southwest Michigan Planning Commission. But off-the-beaten-path America can be revived, she says, by transforming little-used roadways into "green highways" that cater specifically to electric-vehicle drivers and other slow-moving, eco-minded tourists traveling by bicycle or on foot.

"We need innovation in [Michigan]. We've got beautiful scenery. And we see the low-speed, low-range electric-car industry bringing them together," says Gallagher, who is heading up a project to revitalize the U.S. 12 Heritage Trail in her home state. She thinks green corridors could resuscitate Main Streets, in Michigan and across the country. "This could be a small boom to local merchants, healthy-café owners, bed-and-breakfasts. We just want everyone to slow down and enjoy the view; the road is like a destination itself."...