The news today from the Portland Bureau of Transportation (PBOT) is all grim today. In the first of the down-to-the-bone city budget cuts Mayor Sam Adams warned about last month, PBOT announced this afternoon that it forecasts $16 million in cuts next year.

This budget shortfall points out a paradox in Portland's transportation funding—the more people go green and buy less gas, the more the city budget takes a hit. Nearly half of PBOT's general transportation revenue comes from the state gas tax (not counting stimulus funds). While the six-cent gas tax hike went into effect statewide in January 2011, it has generated much less revenue for the state than Oregon thought it would. Instead of a projected $300 million, the hike has raised only $170 million extra statewide. Actually, Oregon Department of Transportation (ODOT) projections for gas tax revenues have been off for the last five years (pdf).

ODOT spokesman Dave Thompson says that gas tax revenues are up 20 percent from last year, thanks to the hike, but some of the lowered revenue is because people are driving less—gallons of gas used in the state declined three percent this past year.

This is a sticky financial balance the city is in. The city's stated goal, under its climate action plan, is to reduce vehicle miles traveled by five percent in Portland. But as long as funding for transportation projects is tied to how much gas people buy, we're going to see hefty budget cuts at a time when we'll need to be investing in alternative, greener transportation.