It looks as if Islanders will have to pay to leave or return to the Island in the future. According to a state study released last Wednesday, the 520 Tolling Commission determined that tolls instituted on I-90 along with the 520 bridge would generate about $1 billion more than just 520 alone. Two of the initial four scenarios suggested by the tolling commission show that tolls on I-90 and 520 would raise a total of $2 billion, compared to the $900 million that only 520 tolls would raise.

Islanders would only be charged half of the proposed rates, according to the study. During the peak toll rate between 3 and 7 p.m. on weekdays, Islanders could expect to pay about $1.62 either way (in 2007 dollars).

Mercer Island State Representative and House Transportation Committee Chair Judy Clibborn said on Friday that the scenarios provide a lot of interesting and different ideas. Clibborn also said she thinks the public input based on these scenarios would benefit the decision-making process in Olympia.

“Not one scenario is going to be used as is,” Clibborn said. “We will take pieces out of each one and make a final scenario. We can pick and choose, like building blocks, and build the best plan to go forward.”

The study listed two of four scenarios to fund a new 520 bridge that would bring a toll on I-90 in both directions. The price would vary depending on the time of day and on weekends.

“These scenarios contain a lot of interesting ideas and different ideas that people can comment on,” Clibborn said. “I was tickled to see options that gave Mercer Islanders a break.”

A presentation to the state Legislature is planned for January when it convenes for a 105-day session. The earliest that a toll would take effect is in 2010, if the legislature approves a toll during its next session. The new bridge will be constructed by 2014, but the entire project and shoreline improvements will be done in 2016.

The proposed scenarios assume that tolls would be charged until the bonds purchased to fund the project are paid off and the duration of tolls would also get decided by the legislature. However, it is possible that tolls could be retained to provide for continued bridge operation and maintenance costs. Whether that would include I-90 or not would also be decided by the legislature in the future. The scenarios also estimate that approximately $100 million of the revenue would go toward adding two-way transit lanes on I-90.

The study also estimates that 20 percent of drivers would avoid SR-520 tolls by alternating their destination. Under the current scenarios being considered, vehicle volumes on I-90 would increase and travel speeds decrease if only 520 is tolled. If both bridges are tolled, there would be less traffic on I-90 and average speeds would increase by 7 mph, up to 40 mph, the study notes. Fewer vehicles would divert from 520 if both bridges were tolled, causing the speed increases on 520 to be somewhat reduced from those found when tolling only 520.

The committee is taking public comments through Aug. 31. Public meetings are scheduled around the Eastside, and one was added to Mercer Island on Monday.

Tolling Open Houses

• Tuesday, July 29 – Bothell

UW Bothell North Creek Events Center

18115 Campus Way N.E.

5 – 7:30 p.m.

• Thursday, July 31 – Renton

Spirit of Washington Events Center

233 Burnett Ave. S.

5 – 7:30 p.m.

• Tuesday, Aug. 5 – Seattle

Naval Reserve at South Lake Union

860 Terry Ave. N.

5 – 7:30 p.m.

•Wednesday, Aug. 6 – Bellevue

Bellevue City Hall

450 110th Ave. N.E.

5 – 7:30 p.m.

•Thursday, Aug. 7 – Kirkland

Kirkland Performance Center

350 Kirkland Ave.

5 – 7:30 p.m.

•Wednesday, Aug. 13 – Mercer Island

Community Center at Mercer View

8236 S.E. 24th St.

5 – 7:30 p.m.

Go to www.WSDOT.org for information or visit www.Build520.org.