Washington State Route 599
SR 599 is 1.75 miles (2.82 km) long and travels on a four-lane freeway located entirely within the city of Tukwila in suburban King County.[1] It begins at a Y interchange with I-5 near Foster Memorial Park, approximately 1.4 miles (2.3 km) north of the Southcenter Mall and the terminus of Interstate 405.The interchange lacks connections to the north side of I-5, which are provided by the parallel Interurban Avenue, and has a direct offramp to the high-occupancy vehicle lanes on southbound I-5.[2] The only intermediate junction on SR 599 is a partial cloverleaf interchange at South 133rd Street near several office parks, including the headquarters of BECU.[5] SR 599 then turns west to travel around a King County Metro bus base, which has a direct onramp to the southbound freeway,[4] and crosses under the light rail tracks at East Marginal Way South.