Hi XZH@CHD!
I’m Anastasia, and I’m a mapper on the OSM team at Lyft. Thank you for your question.
According to the OSM wiki page, the 'ref' tags shouldn’t include cardinal directions in their values (https://wiki.openstreetmap.org/wiki/United_States_roads_tagging#:~:text=The%20name%20and%20ref%20tags%20should%20not%20contain%3A). 
Instead, the cardinal direction is indicated in the route relation: e.g.https://www.openstreetmap.org/relation/108619  (US 101 North) and https://www.openstreetmap.org/relation/71162  (US 101 South). 
So if you need to distinguish between the two one-way roads, you can refer to the route relations for the specific directions. 
Best regards!
