JTNP draws massive numbers of tourists. Plus the main road through my neck of the Mojave (62 and Amboy Rd.) is a popular alternate route linking LA and Las Vegas. You wouldn't believe how much traffic blasts through on weekends and holidays, most without even stopping. It's a lot of city folks driving like they're passing through an uninhabitable wasteland where speed limits don't exist.
The actual number of owners/residents like me out by my hood is on the order of hundreds, and most drive exceptionally slow in the hood because those roads are unpaved washboard insanity.
Airbnb/VHRs becoming a thing there and catering to the national park has made things much worse in terms of local vehicle traffic even on the dirt roads... but the Tortoises were already gone long before Airbnb even existed.
TL;DR: Tourism by automobile is the main problem, exacerbated by the draw of a popular national park. But even without it there's too much thanks to LA<->Vegas traffic.
