But why does the OpenStreetMap Highway tag needs to equal the State's "Functional Class".  Why isn't the state's functional class just an attribute on the road?

https://wiki.openstreetmap.org/wiki/United_States/2021_Highway_Classification_Guidance#Trunk


It says "Between and around the largest population centers, it may be appropriate to tag additional routes as trunk beyond these guidelines, in order to emphasize the presence of multiple high-quality long-haul routes and/or to differentiate them from less-significant surrounding roads."

Rt-20 deserves to be differentiated from less significant roads.
