Washington State’s Puget Sound region could see nearly $7 billion of road and bridge improvement projects and $10.8 billion of light-rail expansions, commuter rail and regional express bus projects if voters approve them next month.

Years in planning, the controversial measure is the most expensive tax package in Washington state history. It would entail an increase in the sales tax of up to .6%, and .8% for motor vehicle excise taxes.

The two-fold ballot measure’s transit portion was drafted by the state agency Sound Transit. The roads segment was developed by the five-year-old Regional Transportation Investment District, a group formed by the Washington legislature to draft a plan for improving transportation in Snohomish, King and Pierce counties. If it is approved, the state’s Regional Transportation Investment District immediately will start construction on projects to improve key transportation corridors, including State Routes 520, 509 and 167, and Interstate 405. That includes 186 miles of new highway lanes. Sound Transit would begin work on plans to add a total of 50 miles of light rail including connections to the Seattle-Tacoma International Airport, building a 2.2-mile streetcar line and constructing new commuter-train and express-bus stations and park-and-ride garages.

Local and state politicians linked the transit and roads plans in 2006, hoping for a win-win solution that would force roads and transit supporters to work together. But so far, the sides are still battling it out and threatening to vote no on the multi-billion dollar package. Environmental groups oppose the highway work and others oppose the transit investment. The Sierra Club says: “We’ve spent the past 50 years building freeways and they keep filling up. New freeway lanes will fill up too. We can’t build our way out of congestion.”

Light-rail opponents say there are too many problems with fixed-guideway systems and that Sound Transit’s proposed East Link, which would run from Seattle across I-90 to Bellevue, would reduce freeway capacity, potentially compromise bridge safety and be unable to adjust to changes in population and employment demographics. “Light rail takes away capacity from roads and highways, which actually increases congestion,” says Jim Horn, chairman of Eastside Transportation Association, a private-sector group working to reduce traffic and increase mobility in the Puget Sound region.

Karl Westby, who worked on the traffic analysis of the I-405 corridor program and owns Redmond, Wa.-based transportation assessment firm Westby Consulting, says that road and highways will only continue to deteriorate and costs will continue to increase if the measure fails. “There are a lot of people who like elements of the package and dislike others. But nonetheless, this is the package that is out there and it does address many of the needs we have,” he says. “If we don’t make the investment now, it won’t be any cheaper in the future. The escalation costs of construction materials will make this package much more expensive even a year from now.”

Floating Bridge, Floating Rail?

The new light-rail system would occupy what are now reversible high-occupancy vehicle lanes in the center of the Homer Hadley Bridge, a 5,811-ft-long floating bridge. A state Dept. of Transportation study released last summer found that vacating the center lanes of I-90 for trains would reduce traffic flow and increase congestion but those effects could be countered by upgrading and increasing capacity on Highway 520 and I-405.

East Link project manager Don Billings says he and colleagues at Sound Transit are confidant in the bridge’s ability to support the weight of the rail line, even though this would be the first such line atop a floating bridge. State transit engineers studied structures with rail in Portugal and Vancouver to understand the logistics of adding trains to I-90. Although these case studies are not floating bridges, the spans suffer vertical and longitudinal shifts caused by trains similar to the movements anticipated for the I-90 bridge if light rail is added. Last September, they simulated train traffic by driving flatbed trucks carrying 296 tons of concrete across the bridge and concluded it could manage rail if joints were reinforced and a significant amount of concrete was shaved off the center roadway.