For the first six months, tolling on the 520 bridge is working as planned, state officials say. Weekday traffic is free flowing for the first time in decades during the peak commute times, and revenue generated by tolling is ahead of forecasts.

This trajectory puts the state slightly ahead of the finance plan, keeping the Washington State Department of Transportation on track with making the debt payments needed to pay for the bridge construction.

Despite forecasts trending ahead in both traffic and revenue, rate increases will go into effect July 1 in order for the state to stay on track with the finance plan to raise $1 billion for a new SR 520 bridge. The increase in July will be the first of four planned 2.5 percent annual rate increases through 2015.

However, no rate increase will occur without the Washington State Transportation Commission reviewing the latest traffic and revenue data to determine if a rate increase is needed each year and at what amount, state officials say.

Starting Monday, electronic overhead signs on SR 520 will remind drivers about the upcoming rate change. The current peak Good To Go! rate of $3.50 will increase to $3.59, and the peak Pay By Mail rate of $5 will increase to $5.13. The other variable toll rates will have similar increases.

“We are headed in the right direction, and it’s looking like our careful planning is already producing positive outcomes,” said WSDOT Toll Director Craig Stone. “That said, this is the six-month mark of a 30-year plan. It’s more important now than ever before that we stay the course.”

So far, more than 80 percent of vehicles crossing the bridge have Good To Go! accounts. The variable tolls are leading drivers to shift their trips to off-peak hours, saving peak-time drivers 12 to 15 minutes per trip. There has been a drop in bridge traffic volumes since tolling began, but the drop has not been as great as forecasted. During the first quarter of bridge tolling, weekday traffic was 15 percent higher than projected. April was 19 percent higher, and May numbers indicate that traffic is now 21 percent higher than projected.

First quarter of the year gross tolling revenue (between January and March) was $12.9 million, exceeding forecasts by six percent. Officials say the trend is continuing into the second quarter with official financial statements to be released this summer.

King County Metro Transit implemented service improvements on the SR 520 corridor to increase options for travelers. This includes more bus service, real-time transit signs, and a new park-and-ride garage that will open in south Kirkland next spring.

“Metro Transit has seen two waves of strong ridership growth so far on the SR 520 corridor,” said Metro General Manager Kevin Desmond. “The first came in the fall of 2011 when we significantly increased transit service; then again this year when tolling began. Overall, we’ve seen a 25 percent increase in bus ridership across the lake in less than a year.”

Just before the start of tolling on Dec. 29, 2011, King County Metro and Sound Transit added 100 daily bus trips across the floating bridge, bringing the weekday service to 700 bus trips and 18 routes. Since tolling began, transit ridership has increased 10 percent. Vanpools on the SR 520 corridor have increased 18 percent. Sound Transit’s service has also grown to serve the increased demand.

“The new riders who are climbing aboard our Express buses serving the SR 520 corridor have contributed to Sound Transit’s overall 12 percent ridership growth from first quarter 2011 to first quarter of this year,” said Sound Transit CEO Joni Earl. “More and more commuters are recognizing the value of using transit to save money and improve their quality of life.”