I also added ref: to the stretch of road under I-70 here. Previously it was mapped using ref:forward and ref:backward, and I understand why, but data consumers want the route designation in the plain ref tag afaict.

This bumps into a semantic point about where specifically a route begins and ends. Route signs are great until they're not, and sometimes they're really not. The MoDOT Transportation Management Center opines that there's technically a concurrency between J and O under the overpass, though, which connects each supplemental route to the opposing interstate ramp, so that's what I'm going with.

I am open to suggestions here about the route termini, but I think a single coherent "ref" tag is still important in 2023/4.