SR 167, also known as the Valley Freeway, begins in Renton at I-405 and continues south through Kent, Auburn, where it interchanges with SR 410, Pacific, and Algona, then interchanges with SR 410, and currently terminates at SR 161. The Valley Freeway was built in stages between 1964 and 1977, with a major upgrade of its southern end in 1986. The Washington State Department of Transportation is currently planning to extend the freeway to Tacoma. SR 167 has HOV lanes between I-405 and SR 18 which also allow single-passenger vehicles to use them for a variable fee, also known as HOT lanes.