Traffic volume
SR 530 is maintained by the Washington State Department of Transportation (WSDOT). The section between I-5 at Island Crossing and SR 9 in downtown Arlington is designated as a Highway of Statewide Significance by the state legislature and as a minor route of the National Highway System by the federal government. WSDOT conducts an annual survey of average traffic volume on the state highway system that is measured in terms of average annual daily traffic. Traffic volumes on SR 530 range from a minimum of 1,100 vehicles near its eastern terminus in Rockport to a maximum of 19,000 vehicles near I-5 at Island Crossing.