The entire route of SR 539 from Bellingham to the Canadian border is perfectly straight and runs due north–south. It serves as an alternate route between Bellingham and British Columbia, bypassing the busier Blaine border crossings. The entire highway is listed as part of the National Highway System, a national network of roads identified as important to the national economy, defense, and mobility; it is also designated as a Highway of Statewide Significance by the state legislature. SR 539 is maintained by the Washington State Department of Transportation (WSDOT), which conducts an annual survey on state highways to measure traffic volume in terms of annual average daily traffic. Average traffic volumes on the highway in 2016 ranged from a minimum of 1,400 vehicles at the Canadian border to a maximum of 37,000 vehicles near Bellis Fair Mall. The Guide Meridian corridor is also served by several Whatcom Transportation Authority bus routes connecting Bellingham to Lynden, Everson, Nooksack, and Sumas.