What's public transit for? Is it a way to provide government-subsidized transportation with the goal of moving the most people possible? Or is it part of a larger strategy to encourage walkable, livable cities with neighborhoods clustered around transit stations?

It's a big debate in Portland, OR, right now. The city -- long hailed as a national leader in its use of transit to shape development -- wants to expand its streetcar line and become the first in the nation to be built with substantial federal money, according to the Oregonian.

But the feds aren't on board:

Think tanks, Democrats in Congress and the White House are fighting over whether the federal government should help cities use streetcars to promote urban revitalization, or simply fund buses that move the most people over the greatest distances for the least amount of upfront money. ...

It's a choice between promoting more cities like Portland and the transit programs that make them possible, or cities like Houston, where express bus service and sprawling development prevails.

At the center of this issue is Small Starts, a newly created Transportation Department initiative -- the first federal program aimed at funding streetcars.

From the Oregonian:

Through the Small Starts program, Congress directed the federal bureaucracy to give streetcar proposals credit not just for moving people efficiently but for spurring growth nearby in the form of restaurants, shops, apartment and condominium buildings. Bus routes, which can easily change, do not show such corollary development.

Still, the Federal Transit Administration has balked at Congress' directive. The transit agency proposes to judge streetcars mainly by how quickly they move people over great distances. Economic development and urban housing could be considered, but couldn't be central to judging a project's worth.

I wrote in the July issue of Governing about a similar debate over the purpose of transportation funding (although minus the federal issue) in Charlotte, NC.