A continuous cross-continental active transportation trail would pay for itself in less than five years in visitor spending alone, a new analysis argues — and it could have a big impact on the car-free transportation landscape in the communities it runs through, too.

According to a new report from the Rails-to-Trails Conservancy, completion of the Great American Rail-Trail — a 3,700-mile shared-use path stretching from the Capitol steps in Washington, D.C. to the coast of Washington State — would generate more than $350 million per year in economic activity in the form of tax revenue, income for workers, and tourism dollars for local communities.

That's less than a third of the $1-billion the group estimates it'd take to fill the gaps in the existing trail, which is 53 percent complete today. And when that happens, experts say the economic impact will be huge — and so will the mobility impacts for residents of the towns the route ones through.