Interstate 5 is the only north-south interstate freeway in Washington state. Just through Seattle it carries 280,000 vehicles per day. WSDOT is working on improving traffic flow and travel on this important route. Between Seattle and Shoreline we recently completed and continue work on improvement projects to make your commutes safer and shorter. We are busy building noise walls, repairing and replacing aging concrete slabs, strengthening overpasses and ramps, and adding more lanes. The following are projects on I-5 and on connecting routes that you should know more about:
Projects We are Building in 2007
Future Improvements
Connecting Routes
Completed Projects
Projects We are Building in 2007
I-5 - Dearborn to Dayton Avenue Fiber Replacement, Seattle - Shoreline
This summer crews will replace and upgrade the fiber optic communication cable between the I-5/I-90 interchange and our traffic management center located in Shoreline, where we will also upgrade communications equipment. The new fiber optic cables and equipment will improve the reliability and capacity of the communications system.
I-5 - Spokane Street to I-90 Bridge Repair, Seattle
In summer 2007 construction begins on this project which addresses a portion of I-5, just south of downtown Seattle, that is elevated on a bridge deck. We will resurface 1.13 miles of freeway and replace or repair expansion joints. More than 260,000 cars travel this stretch daily. Over 21,000 of them use the I-5 southbound exit to the West Seattle Bridge and over 19,000 of them use the northbound I-5 exit to I-90. This will create a smoother, safer ride for drivers and eliminate the need for constant and disruptive repairs.
Future Improvements
I-5 - Spokane Street Interchange Illumination Rebuild, Seattle
In early 2008 we will remove and replace the illumination system and signing at the I-5/Spokane Street interchange which will improve safety and visibility for drivers.
I-5 - 5th Ave. NE to NE 92nd Street Noise Wall, Seattle
We are currently studying locations in this area for construction of up to four noise walls. Residents of Seattle's Maple Leaf, Licton Springs, and North Green Lake neighborhoods will experience a noise reduction up to 10 decibels.
I-5 Roanoke Vicinity Noise Wall, Seattle
We’ve finished the first two stages of constructing noise walls on I-5 in Seattle along Boylston Avenue and the Harvard Avenue. We have now convened an Expert Review Panel to help determine the foundation for each of the three walls included in Stage 3.
I-5 Pavement Reconstruction and Bottleneck Improvement Projects, Seattle - Tukwilla
Planning is underway to replace 16 miles of concrete on I-5 from Tukwilla through downtown Seattle to Northgate. WSDOT engineers are recommending that the existing nine inch-thick pavement on I-5 between downtown Seattle and Tukwilla be removed and replaced with thicker pavement and reinforced with steel bars at the joints. The thicker concrete will ensure at least another 40 years of service, and the bars will help the roadway behave like a single unit rather than like individual concrete panels. This will help minimize the rough "thump, thump, thump" motorists now hear and feel as they drive on I-5 through Seattle. Work is anticipated to begin in 2009. Construction will be coordinated with other transportation projects in the area including the Alaskan Way Viaduct project, the SR 520 Bridge Replacement project, Light Rail, and I-405 and SR 509 improvements.
I-5 Boston Street to Shelby Street Noise Wall Project, Seattle
This is the third stage of the I-5/Roanoke Vicinity Noise Wall Project. We will construct noise walls to reduce freeway generated noise along the west side of I-5 in the vicinity of E. Boston and E. Shelby Streets. Construction begins in 2008.
I-5 Northeast 50th Street Signal Rebuild, Seattle
We will replace the signal system at the north and southbound ramps at Northeast 50th Street and replace signing as needed and make sidewalk and pavement repairs. Crews will install a signal controller connect it to the city of Seattle system. Look for construction to begin in Spring 2008.
I-5 Ship Canal Bridge Noise Mitigation, Seattle
We will complete an analysis and test for feasible noise reduction elements on the I-5 Ship Canal Bridge. The project also provides funding for test implementation.
I-5 5th Avenue NE to 92nd Street Noise Wall, Seattle
We will add noise barriers on the east and west side of I-5 from 5th Avenue NE to 92nd Street improving the outdoor environment and reducing the existing traffic noise levels. Work begins in 2009.
I-5 James Street and Spring Street Ramp Terminals Signal Rebuild, Seattle
We will remove and replace the signal system at the I-5 James Street and Spring Street ramp terminals, and make sidewalk and pavement repairs. Look for work to begin in spring 2008.
Connecting Routes
SR 99 - Alaskan Way Viaduct and Seawall Replacement, Seattle
This project will address the deteriorating and seismically vulnerable viaduct and seawall. About 110,000 vehicles use the viaduct each day. WSDOT, the Federal Highway Administration and City of Seattle are moving forward with early safety and mobility improvements in the north and south end that will replace or repair over half of the seismically vulnerable viaduct. An alternative for the central waterfront portion will be decided through a collaborative process.
SR 99 - Shoreline Aurora Ave. - N Corridor Transit/HOV Lanes, Shoreline
This project, currently in Phase 1, will improve safety and traffic flow on a three mile stretch of State Route 99. WSDOT is working with the City of Shoreline to redesign and upgrade the road for the 38,000 to 45,000 vehicles that use it everyday.
SR 520 - Bridge Replacement and HOV Project, Seattle - Bellevue
The Evergreen Point Bridge is vulnerable to windstorms and earthquakes and needs to be replaced. The 1.5 mile long, 42 year old floating bridge could be replaced with either a 4 or 6 lane facility. Both designs include pontoons large enough to support future high capacity transit.
I-90 - Two-Way Transit Lanes & HOV, Seattle - Bellevue
WSDOT is working with Sound Transit to add HOV lanes to the outer roadways. Up to 14,000 vehicles use the reversible center roadway daily, which is limited to HOV traffic. This means there are no HOV lanes running eastbound in the mornings, or westbound in the evenings.
SR 99 - Aurora Bridge Suicide Prevention Project, Seattle
After a recent increase in the number of suicide attempts, WSDOT is working with the City of Seattle to prevent suicide jumps on the Aurora Bridge. The City of Seattle is installing suicide prevention signs and phones that connect people to a crisis hotline. We are considering additional suicide prevention measures.
Completed Projects
I-5 - North Seattle Bridges - Seismic Retrofit, Seattle-Shoreline
We upgraded seven bridges on Interstate 5 in Seattle and Shoreline. The upgrades will help the structures withstand earthquakes. Crews strengthened 22 columns with steel jackets and added devices known as catcher blocks to prevent girders from falling off the bridge piers. This project was part of WSDOT’s seismic retrofit plan to strengthen more than 900 bridges statewide to better withstand earthquakes.
I-5 NE 175th St. to NE 205th St. - NB Auxiliary Lanes, Shoreline
We added an auxiliary lane from NE 175th St. to NE 205th St. in Shoreline. This will help relieve congestion and improve safety by providing more room for motorists to speed up and merge when getting on and off the freeway. We also widened existing freeway lanes and shoulders to enhance safety. Crews restriped the existing northbound 11-foot lanes to 12 feet and the existing 8-foot shoulders to 10 feet.
I-5 James to Olive Paving, Seattle
Crews removed 350 truckloads of old asphalt and poured 700 truckloads of new concrete to resurface a one mile span on I-5, between James and Olive streets, through downtown Seattle.