SR 509 continues north onto Marine View Drive through the city of Normandy Park and into SeaTac, where it turns southeast onto Amabaum Boulevard and Des Moines Memorial Drive to a trumpet interchange, the southern terminus of a limited-access freeway section of SR 509.
SR 509 continues north onto Marine View Drive through the city of Normandy Park and into SeaTac. It turns southeast onto Amabaum Boulevard to a trumpet interchange of SR 509. It turns southeast onto Des Moines Memorial Drive to a trumpet interchange of SR 509. A trumpet interchange is the southern terminus of a limited-access freeway.