- State Route 99 (SR 99), also known as the Pacific Highway, is a state highway in the Seattle metropolitan area, part of the U.S. state of Washington. It runs 49 miles (79 km) from Fife to Everett, passing through the cities of Federal Way, SeaTac, Seattle, Shoreline, and Lynnwood. The route primarily follows arterial streets, including Aurora Avenue, and has several freeway segments, including the tolled SR 99 Tunnel in Downtown Seattle. SR 99 was officially named the William P. Stewart Memorial Highway by the state legislature in 2016, after a campaign to replace an unofficial moniker honoring Confederate president Jefferson Davis.