Will toll be needed on I-90 bridge, too?

Legislative transportation leaders Monday downplayed assertions by state Treasurer Mike Murphy that tolls would likely be needed on both Lake Washington floating bridges to help pay for a new six-lane Evergreen Point Floating Bridge.

Previous financing discussions have revolved around tolls only on the new bridge. But Murphy said tolls would be necessary on Interstate 90 as well — unless the state comes up with more money to pay for the new bridge.

Murphy said he would not issue construction bonds unless he's confident the money can be repaid. "We have this real simple rule around here: When we borrow money, we pay it back, and we pay it back on time," he said.

However, Murphy is only one of three people on the state finance committee whose approval is needed for any bond issue. The other members are the governor and lieutenant governor.

The chairwomen of both the Senate and House transportation committees said Murphy's concerns are premature.

"It's too early to make those decisions," said Mary Margaret Haugen, D-Camano Island, who leads the Senate Transportation Committee.

The state has not yet designed the bridge, so bonds to finance the project won't be sold for several more years, Haugen said.

House Transportation Chairwoman Judy Clibborn, D-Mercer Island, said everyone in Olympia thinks the state will come up with more money for 520.

Clibborn said there likely would be tolls for "HOT lanes" on I-90 — high-occupancy lanes that single drivers could use for a fee — but that the state should look for ways to avoid tolls for general-purpose I-90 lanes.

Murphy said he agrees with a recent report produced independently for the state Department of Transportation that concluded tolls on only the 520 bridge would result in a 31 percent to 33 percent financing shortfall.

The report is based on the assumption that a new six-lane bridge, coupled with improvements to I-90, would cost $4.4 billion. But only $1.7 billion in financing has been identified, the report states, including $1.1 billion from a regional transportation plan yet to be approved by voters. Tolls would be used to finance the remaining $2.7 billion.

Murphy said he thinks tolls should be charged on the I-90 and 520 bridges "as soon as possible" — even before a new 520 bridge is completed.

"I don't get cash flow until tolls come in, and otherwise we are paying interest on interest," Murphy said.

He reasoned that introducing a toll only on 520 would divert about 30 percent to 50 percent of traffic onto I-90.

"Then we get a parking-lot scenario on 90 and a financial problem on 520," he said.

Clibborn, however, said the analysis she has seen indicates drivers would use 520 even if it were the only Lake Washington bridge with a toll, because they wouldn't want to navigate busy highways such as Interstate 405 to avoid the toll.

The report cited by Murphy notes that federal permission would be needed to charge tolls on I-90, because federal law generally prohibits tolling on interstate highways.

The report recommends the state set up an independent tolling agency to set tolls — an agency that could presumably expand its purview over time.

Murphy said he's reluctant to estimate how much drivers could expect to pay to cross the bridges, because any number he comes up with is likely to be viewed as final.

Jennifer Ziegler, the transportation-policy adviser for Gov. Christine Gregoire, said Murphy's comments and the report provide another tool for the Legislature to use in devising a 520 financing plan.

Ziegler said Gregoire has told lawmakers they need to find more money for the project.

Nick Perry: 206-515-5639 or nperry@seattletimes.com