[spott]

I expect some of these roads haven't seen anyone (person or car) for years.

"Roads" don't really seem to die. Once they are mapped, they show up forevermore -- even if no-one is taking them and no-one is checking that they are still navigable.

[s0rce]

The forest service, at least in some of the more "popular" areas in WA, CA and OR sometimes rates the road on their motor vehicle use map so you know the likelihood you'll actually be able to use it. On BLM land I've found map roads that there is little no evidence of at all.

[scruple]

> even in ... no-one is checking that they are still navigable.

Which can be a startling and frustrating experience in a bad, or even a good, situation...