I live about a dozen miles from the Googleplex in the Santa Cruz Mountains and Apple Maps has roads all around me that do not exist: at best jeep trails but mostly logging roads from 150 years ago that are nothing but forest today, barely hiking trails at this point. Apple Maps is a joke outside of major cities and has been since its debut.
There's no way to detect that via signals because if there's no cell reception, people's phones won't report back where they are/aren't driving. So you'd have to report it by hand if you care.
Anyway, if it's showing on a consumer map that probably means it was never removed from official data sources like USGS TIGER.
