Tolling: Now rather than later

Tolls on the Highway 520 floating bridge may not be welcome, but they are necessary.

Unless big, expensive bridges are paid for with federal money, they have to be paid for, in part or all, by the people who use them.

Think of our state's floating bridges: the Hood Canal Bridge had a toll for many years. The newer Interstate 90 bridge did not, being a federal highway, but the original Mercer Island bridge had one. Today's Highway 520 bridge, built in 1963, charged drivers 35 cents each way — the equivalent of $2.50 in today's dollars.

The new Tacoma Narrows Bridge is tolled, and the planned, new Interstate 5 crossing at Vancouver will be tolled. Realistically, the questions about tolling the new 520 bridge are when and how much. To help answer the questions, the state Department of Transportation offers a new study based on a computer model.

A key question is whether to start tolling when the new bridge is finished in 2016, or start early, in 2010. The argument for tolling later is that it's not fair to charge people for a thing until they have it. Dino Rossi, the Republican candidate for governor, has made that argument, as have others.

But there is a counterargument: A toll set in 2010 can be set lower. More realistically — since the toll in the state's plan pays for less than a quarter of the bridge — a toll set in 2010 can pay for more of the bridge.

Tolling should reduce congestion. Tolls will be collected automatically so users will not stop at toll booths. Tolls will also vary by time of day, setting a penalty for driving in the peak hours. The study estimates that a $3.80 one-way toll on afternoon commuters would increase speeds to 44 mph from 25 mph because of the penalty effect. The same plan has only a 90 cent toll at night. (The tolls are, deceptively, in 2007 dollars. At a 4 percent rate of inflation, a $3.80 toll rises to $5.40 in 2016.)

Another question is whether to toll I-90 as well. In the state's study, this almost triples the amount of money raised. This is delightful for the state, but this is even more obviously unfair than charging in advance, and we are reluctant to support it.

The state's study had one particularly interesting result. It estimates that because of tolls, as many as 22 percent of drivers would stop crossing the lake altogether. They would move or change jobs. A smaller number would go around the lake. An even smaller number — only about 3 percent — would car pool or take the bus.

There is going to be big demand for the new bridge. Users will need to accept a toll, and the sooner the better, so the state can get moving on building it.