After exiting the canyon, the freeway enters the city of Auburn and intersects West Valley Highway, signed as SR 181 until 1991, and SR 167, named the Valley Freeway, in a complex hybrid partial cloverleaf and diamond interchange. SR 18 continues east past The Outlet Collection Seattle and over the mixed-use Interurban Trail as it approaches a folded cloverleaf interchange with C Street Southwest and a partial cloverleaf interchange with SR 164 at Auburn Way. The freeway passes an exit serving Green River Community College via Southeast Auburn-Black Diamond Road before crossing over the Green River into unincorporated King County.