 Passing Elk Plain and suburban areas , the highway enters Spanaway near the Fort Lewis boundary where SR 7 intersects SR 507 , which continues southwest to Chehalis . The Mountain Highway becomes Pacific Avenue and enters Parkland . Shortly after 112th Street , the roadway has a partial cloverleaf interchange with SR 512 , which uses 108th Street South as two ramps . Leaving Parkland and entering Tacoma , Pacific Avenue turns east as 38th Street and then has another partial cloverleaf interchange with a short freeway and the proposed route of SR 7 , which is used by the roadway . The freeway was the busiest segment of the highway in 2007 , with an estimated daily average of 27 @,@ 000 motorists . The median of the freeway is the Tacoma Rail route and at the northern terminus is an interchange with Interstate 5 ( I @-@ 5 ) . SR 7 ends at the interchange , located near the Tacoma Dome , but continues north parallel to the railroad to a single @-@ point urban interchange with SR 509 as I @-@ 705 . 
