Toll on new 520 bridge could be $6.85 round trip, state study says

Motorists might have to pay up to $6.85 for a round-trip commute on the new Highway 520 floating bridge, according to a new state study released today.

That's in today's dollars. Because of inflation tolls would be higher by the time the new six-lane bridge is built in 2016, assuming the state can make a design decision soon for the difficult Montlake interchange.

Even then, the tolls would fill only about half of the current funding gap — $1.5 billion to $2 billion — for the $3.9 billion construction project across Lake Washington.

To launch tolling before the new bridge is built would only raise slightly more money; that's because officials wouldn't charge nearly as much as they would tolling only after the new bridge is built.

Other tolling scenarios are far more lucrative — raising well over $2 billion — but they require also tolling the neighboring Interstate 90 bridge at the same rate, the study says.

Some motorists would detour to Highway 522, around the north end, but not in great enough numbers to greatly affect speeds there, the study predicts. But any toll would steer some people to transit, or to avoid crossing the lake.

The new information will be used by a "520 Tolling Implementation Committee," which will report back to Gov. Christine Gregoire and the Legislature next year. Members are state transportation Secretary Paula Hammond; state Transportation Commission member Richard Ford; and Bob Drewel, executive director of the Puget Sound Regional Council. The old four-lane bridge, built in 1963, is at risk of failure in an earthquake or severe windstorm. Studies about expanding its capacity began two decades ago.

Public open houses are planned the next two weeks. More information at www.build520.org.

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