SR 500 begins at an interchange with I-5 near downtown Vancouver, at the level of 39th Street. It runs eastward along an expressway to a traffic signal controlled intersections with Falk Rd. and NE 54 Ave. It then continues as an expressway past Westfield Shopping Town Vancouver (The Vancouver Mall) to a cloverleaf interchange with I-205. It continues as a freeway for short period before traveling over local roads to the Padden Parkway where it meets with the southern terminus of SR 503, the route then turns eastward to follow Padden Parkway to its terminus at Ward Rd. which SR 500 follows a short distance to N.E. 162nd Ave., where it turns south to 4th Plain Rd. From there it follows various local roads southeastward to its terminus just southeast of downtown Camas where it meets SR 14.
Due to a high accident rate and traffic volumes, Washington State Department of Transportation is converting the expressway section of SR 500 between Interstate 5 and SR 503 to a freeway in phases. Three of the five planned interchanges have been completed, at N.E. Andresen Rd. (1995), N.E. Thurston Rd. (2002), and N.E. 112th Ave./N.E. Gher Rd. (2004). Two more interchanges and an overcrossing will complete the freeway at N.E. St. Johns Rd. (interchange), N.E. 42nd Ave. (overpass), and N.E. 54th Ave. (half-interchange, eastbound only).