Washington State Route 99
State Route 99 (SR 99) is a 49.13-mile-long (79.07 km) state highway serving the Seattle metropolitan area in the U.S. state of Washington. A 2-mile (3.2 km) gap divides the highway into two segments, between the interchanges of SR 518 and SR 599 in Tukwila. The southern segment of SR 99 travels north from Fife through the cities of Federal Way, Des Moines, Kent, and SeaTac to Tukwila. The northern segment of SR 99 continues north from Tukwila through Seattle, Shoreline, Edmonds, Lynnwood, to the Broadway Interchange in Everett.
Route description
Southern segment
SR 99 originates at Interstate 5 in Fife, near its own intersection with 54th Avenue E. From there, it heads eastward to Federal Way where it becomes Pacific Highway South and intersects SR 18 just west of its interchange with I-5. It then begins to travel north, through Des Moines, overlapping SR 509 for a few miles. The route becomes a little difficult to identify for several miles, as there are no reassurance signs until entering SeaTac. Once there, it becomes International Boulevard and forms the eastern boundary of the Seattle-Tacoma International Airport until crossing SR 518, where the southern division ends.
