ElliottPlack
I made a couple of tweaks just now based on my cold, wet survey today.

1. Extended the pavement to the back of the building. Unclear if that is county maintained or not.
2. Set the path to track. This is precisely a track in OSM parlance, which is an unmaintained roadway suitable for utility vehicles.
3. I set motor vehicle access to no, because if you read the wiki, access=official is not applicable. For things that say "official use only" in the USA, set the motor vehicle access to no.
4. The track is mostly on MTA land, and I don't think they would prohibit cyclists. 99% of the time these "official use only" signs are meant to discourage cars.

https://wiki.openstreetmap.org/wiki/Tag:access%3Dofficial