system
A chat on subreddit /r/NoStupidQuestions
human
School transportation, too.  The pay is decent, most companies pay for training (CDL class B) and extra hours can be picked up for things like field trips and sports activities.
gpt
Around us, they are in such short supply schools are starting late and change their hours of operation so the bus drivers can pull more routes than normal. They keep increasing benefits and I get weekly emails about opportunities.  I think now they are offering free BJs in between routes and still can't fill the slots.  They've made the coaches/advisors of most of the sports and activities get their licenses and drive the teams to the games/activities due to the shortage.

So, I'm guessing job security would be pretty good :)