Is it really so steep that you can't cross it? I don't recall anything like that, but if you're sure, I believe you ;)
Yes, you can either add embankment=right to a part of the road (but I think it won't be rendered anywhere), or restore the cliff line as an earth bank. You can use https://level0.osmz.ru/ (some documentation: https://wiki.openstreetmap.org/wiki/Level0 ). Log in, enter "w1307128545.1" into the upper field, then in the large field change "1307128545" to "1307128545.3" (or ".2" or ".4", I can never remember right, but it will tell you if you enter something wrong), change the cliff tag to the earth_bank key and hit "Upload to OSM".