Like many other metro regions, Central Puget Sound is dealing with the consequences of decades of exponential growth in the use of regional highways and state routes. While 2008 saw a modest drop-off from the previous year in vehicle miles traveled around the nation, due to spiking gas prices, that made little difference in terms of highway congestion and wear and tear. Chronic under-investment for years has left our region's major highways badly in need of repair, and in some cases, replacement. Major increases in population and regional traffic also mean some new roads or road extensions need to be built, in Pierce County and Southwest King County, for example.

Deep Bore Tunnel/State Route 99

The 1953-vintage, seismically vulnerable Alaskan Way Viaduct on State Route 99 in downtown Seattle needs to be replaced. After an extensive government and community stakeholder review of eight finalist options, an inland downtown deep-bored tunnel option long supported by Cascadia Center was chosen as the preferred alternative by Governor Chris Gregoire, Seattle Mayor Greg Nickels, and then-King County Executive Ron Sims in early 2009. The state had already set aside $2.4 billion for the Viaduct replacement, and $400 million more was to be raised by time-variable electronic tolling of the tunnel. The tunnel itself is projected to cost between $1.2 and $2.2 billion; the total project - including surface street, transit, utility and other improvements - $4.2 billion. Funds in excess of the state's $2.8 billion will come from the city, county and Port of Seattle.To guard against cost overruns, the state will employ so-called 'design-build' contracting procedures plus careful site evaluations, preliminary engineering and special cost estimating methodology.

After years of dispute over how to replace the Viaduct, the political accord of top elected officials on the deep bored tunnel solution marks a major turning point. Building the single-bored, stacked four-lane tunnel, combined with increased transit service and electronic tolling of the tunnel with higher rates at peak hours, will prove to be a farsighted move - ensuring adequate capacity for downtown bypass traffic on SR 99; avoiding the massive disruptions to waterfront businesses from construction of another elevated roadway; and opening up the city's waterfront to enhanced recreation and carefully planned development which will boost the local tax base considerably and help pay for some of the project's transit elements.

SR 99 and the planned tunnel aren't in a vacuum. It will be important for policy-makers to toll the Seattle express lanes of parallel I-5, to minimize potential effects of SR 99 tunnel toll avoidance. This will also help fund needed I-5 work, which totals $2 billion just between downtown and the city's north end. At the same time, some portion of tolling revenue from I-5 and the SR 99 bypass tunnel should be dedicated to expanded transit service in that corridor, such as more express buses.

State Route 520 Floating Bridge

Meanwhile, the State Route 520 Floating Bridge from Seattle across Lake Washington to Eastside job centers must also be replaced due to major safety risks from windstorms and earthquakes. The tab is expected to be roughly $5 billion to $6 billion, with electronic time-variable tolling expected to control peak-hour solo driver traffic volume and raise several billion toward construction costs. Tolling is likely to begin by 2010 on the old bridge and perhaps at some point also on the parallel Interstate 90 bridge to the south. SR 520 and I-90 comprise a single, major east-west corridor and tolling in that corridor should fund infrastructure improvements, vehicle capacity management and high-capacity, high-speed transit.

Other Roads

According the state, Interstate 5 needs $2 billion worth of work between downtown Seattle and the city's north end to fix congestion-causing interchanges and badly deteriorated pavement. US Route 2 in Snohomish County, a notoriously unsafe and deadly corridor, requires another $2 billion in work, according to the state. State Route 167 in south King and Pierce counties, needs to be extended to the Port of Tacoma to improve regional freight mobility. Funding is not secured. The envisioned Cross Base Highway in Pierce County would help ease chronic congestion on I-5 and arterial roads, but is hundreds of millions of dollars short. State Route 509, an important north-south connector in southwest King County, needs $1 billion for completion.

Elsewhere in Washington State, Clark and Spokane counties are struggling to fund major highway projects to ease congestion and handle future growth.

Funding solutions for Central Puget Sound road projects must include broader development of regional electronic time-variable tolling, various local and regional taxes and fees approved by voters, continued state investment, and a more welcoming approach to private investment.