U.S. Transportation Secretary Mary Peters wants to lower gas taxes. But in return, drivers would pay tolls on highways around the country, under a "congestion-pricing" system. Tolls would rise in heavy traffic and drop in light traffic, in an effort to r

U.S. Transportation Secretary Mary Peters wants to lower gas taxes.

But in return, drivers would pay tolls on highways around the country, under a “congestion-pricing” system. Tolls would rise in heavy traffic and drop in light traffic, in an effort to reduce congestion at peak times.

Peters aired her views Friday to the Washington Roundtable, a group of business executives who have backed transportation campaigns. She argued that Americans lack “investor confidence” in higher gasoline taxes, because she said the money is spent inefficiently and hasn’t reduced congestion.

Toll income should eventually replace the federal gas tax, she said.

“I think we should step it down in time, as these new revenue sources go on line, and see it go away,” Peters said.

The federal government collects 18.4 cents a gallon in gas taxes. When that is coupled with the state’s gasoline tax, Washington residents will pay a total of 55.9 cents a gallon when the latest increase kicks in July 1.

Seattle plays a huge role in Peters’ tolling argument.

Her department is offering $139 million to launch congestion-price tolling on the Highway 520 floating bridge by September 2009.

Peters said the federal government will yank a similar grant from New York City if the state fails on Monday to approve a toll for driving into Manhattan.

The Washington Legislature passed a bill supporting tolls but didn’t set specific rates or timetables, leaving those tough decisions until next winter’s session. Meanwhile, the state Department of Transportation figures it could take a year to design, build and test a toll system for Highway 520.

Peters wants the state to design its toll project and prepare bidding documents well before the 2009 Legislature to meet the federal deadline. Tolls might be $6 to $7 round-trip at peak times, state studies show.

She also said federal law allows tolls on the nearby Interstate 90 Floating Bridge — but local leaders must decide whether to impose those.

She praised an experiment on Highway 167 that begins April 26, when solo drivers will be able to pay to enter the uncrowded high-occupancy-vehicle lanes.

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com