There are many things that affect how WSDOT schedules projects.
It comes down to time and money.

Money The Washington State Legislature gives WSDOT a list of projects, the money to complete those projects and a schedule. WSDOT is working through the 2003 and 2005 gas tax-funded projects now.

Construction deadlines WSDOT, SDOT, King County and multiple utility companies are working toward two construction deadlines: the Alaskan Way Viaduct and Seawall Replacement project and the SR 520 Bridge Replacement and HOV project in 2010. If we are unable to complete safety and preservation work on alternate routes and parallel traffic corridors in 2009, we may not have the time, resources and traffic capacity to return to the work on these alternate routes until 2014.

Planning, coordination and outreach By the time we get on the road this spring, we will have nearly two years worth of planning and coordination with other agencies under our belt. We are doing our best to keep construction schedules streamlined.

Our grassroots outreach to the public, business and community groups began in the fall 2008. Outreach to the media began late fall and continues throughout the construction season.