you're assuming that they even make it to the truck stop, it isn't just paper litter along the border highways & interstates. Especially between Nogales & Tucson.
I drove a semi for a major carrier for 2-1/2 years; they had a terminal (pickup point, load-swap point) on the north side of Laredo and I’d watch the Mexican drivers bring their loads in, slam them into a slot, slam onto another trailer and gallop off to Manana land at high speed. No, I don’t assume anything about Mexican trucks or drivers. Glad I don’t do that any more. There’s about a 60% turnover rate in the driver workforce in this country, IIRC, and the fact that a truck driver is the ONLY worker required to account for his time 24 hrs. a day is probably part of it.