sentences:  The highway is designated as a major freight corridor and serves as an alternative route to the 24-hour Sumas border crossing from Interstate 5, which intersects SR 539 in Bellingham.SR 546 is designated as a Highway of Statewide Significance and is listed as part of the National Highway System, a network of roads identified as important to the national economy, defense, and mobility.The Washington State Department of Transportation (WSDOT) estimates that approximately 5,500 to 9,700 vehicles use the highway on a daily basis, based on annual average daily traffic data.