| State Route 900 | ||||
|---|---|---|---|---|
|   Map of King County in western Washington with SR 900 highlighted in red | ||||
| Route information | ||||
| Auxiliary route of I‑90 | ||||
| Defined by RCW 47.17.825 | ||||
| Maintained by WSDOT | ||||
| Length: | 16.20 mi (26.07 km) | |||
| Existed: | 1964 – present | |||
| Major junctions | ||||
| West end: |  I‑5 in Tukwila | |||
|  SR 167 in Renton   I‑405 / SR 169 in Renton | ||||
| East end: |  I‑90 in Issaquah | |||
| Location | ||||
| Counties: | King | |||
| Highway system | ||||
| 
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State Route 900 (SR 900) is a 16.20-mile-long (26.07 km) state highway serving suburban King County, Washington. It travels east from an interchange with Interstate 5 (I-5) in northern Tukwila through the city of Renton and into the Issaquah Alps to reach the city of Issaquah, where the highway ends at an interchange with I-90.
SR 900 begins as an extension of Martin Luther King Jr. Way South at an intersection with Boeing Access Road, east of its interchange with I-5 under an elevated section of the Central Link light rail line, in the Allentown neighborhood of northern Tukwila. The four-lane highway splits at a basketweave interchange with I-5, with the southbound lanes of SR 900 traveling over the freeway twice. The roadway continues southeast into Skyway whilst parallel to I-5 and the BNSF South Seattle railyard. SR 900 turns east and becomes Sunset Boulevard as it enters Renton, following the Black River and a BNSF branch railroad, to an intersection with SR 167 at Rainier Avenue.