I would say yes to an extent. Numbered roads are also a factor in OSM because traditionally, a Interstate(motorway) is more important than a US Route(primary or higher), more important to a primary state route(secondary or higher), more important than a county, secondary state, or farm route(tertiary or higher), more than an unnumbered road(minor or higher). Also River Road and Seneca Road come back to I-270 between Rockville and Gaithersburg