How to annotate freeway on/off ramps?

Consider https://www.openstreetmap.org/#map=17/42.85888/-73.77169. As I write this, I-87 is annotated as having 3 lanes south of the on/off ramps (south of 146). However, the off ramp starts all the way back at the Sitterly Road overpass, and the on ramp doesn't fully merge until just before the emergency vehicle turn-around only slightly north of said overpass. Accordingly, there are actually four lanes for these stretches.

What is the correct way to model this?

I'm thinking, for the off ramp, the highway:motorway_junction should be pushed back, the relevant segment made 4-lane, and possibly get change:lanes=yes|yes|yes|no; the location where the ramp splits from the freeway should be left as-is (currently where the ramp actually separates from the freeway). For the on ramp, make the relevant segment 4-lane with change:lanes=yes|yes|not_right|yes. Is that the sensible thing to do, or is there another way?