How many interstate highway systems does Washington state have and list them?

The Washington State Department of Transportation (WSDOT) currently maintains seven major interstate highways:

* Interstate 5 (I-5): This is the main north-south interstate highway in Washington state, running from the Canadian border at Blaine to the Oregon border at Ridgefield.

* Interstate 90 (I-90): This is the main east-west interstate highway in Washington state, running from the Idaho border at Spokane to the Puget Sound area.

* Interstate 405 (I-405): This is a spur route of I-5 that runs from Tukwila to Lynnwood.

* Interstate 182 (I-182): This is a short interstate highway that runs from I-90 in Richland to the Hanford Nuclear Site.

* Interstate 205 (I-205): This is a bypass route of I-5 that runs from Vancouver to Portland, Oregon.

* Interstate 395 (I-395): This is a short interstate highway that runs from I-90 in Spokane to the Idaho border.

* Interstate 512 (I-512): This is a short spur route of I-5 that runs from Federal Way to Tacoma.