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About the Project: I-5/SR 509 Creates New Capacity, Saves Time and Money, Improves the Environment
• Provides new capacity on I-5 by adding 18.5 new lane miles and truck climbing lanes where needed. An estimated 50,000 vehicles will use the new SR 509 each day.
• Fully connects SR 509 to I-5, expanding access into Sea-Tac International Airport, serving future terminal and passenger growth.
• Creates a direct freeway connection at South 288th Street for the Green River Valley warehouse and distribution complex.
• Includes a new exit with connections to the Sound Transit light rail station at South 200th Street.
• Provides a new direct connection for passengers and freight between the airport area and downtown Seattle.
• Saves motorists and trucks 11 minutes or more on trips around the seaport and Green River Valley. Saves airport travelers 10 minutes per trip coming from the south.
• Relieves congestion on I-5 with this shorter route, reducing emissions, improving air quality and lowering fuel consumption.
• Improves the environment with earlier construction that includes new wetlands and habitat improvement in the Des Moines Creek basin.
Port of Seattle image by Don Wilson
Aerial photo of Kent Valley Distribution and Manufacturing Center courtesy of City of Kent