There has never been a totally unambiguous definition of road classifications in the US. In most places, US highways are given the primary designation, and state highways are given the secondary designation, except where they clearly meet motorway or trunk classification. So this highway meets part of the Primary definition, and part of the Secondary definition. The OSM usage of primary and secondary roads also may not match common usage by other organizations such as the state highway department. In [edit]In the end, routers often do not take only use road classification into account when choosing a route - they generally use anything above 'service' for through paths. if there are no additional road attributes. The more important attributes for router hints are traffic signals, road width, lane count, speed limit, and turn lane tagging.

There has never been a totally unambiguous definition of road classifications in the US. In most places, US highways are given the primary designation, and state highways are given the secondary designation, except where they clearly meet motorway or trunk classification. So this highway meets part of the Primary definition, and part of the Secondary definition. The OSM usage of primary and secondary roads also may not match common usage by other organizations such as the state highway department. In the end, routers often do not take road classification into account when choosing a route - they generally use anything above 'service'. 'service' for through paths. The more important attributes for router hints are traffic signals, road width, lane count, speed limit, and turn lane tagging.

There has never been a totally unambiguous definition of road classifications in the US. In most places, US highways are given the primary designation, and state highways are given the secondary designation, except where they clearly meet motorway or trunk classification. So this highway meets part of the Primary definition, and part of the Secondary definition. The OSM usage of primary and secondary roads also may not match common usage by other organizations such as the state highway department. In the end, routers often do not take road classification into account when choosing a route - they generally use anything above 'service'. The more important attributes for router hints are traffic signals, road width, lane count, speed limit, and turn lane tagging.