The federal mine safety inspector considered citing the mine operator for violating rules requiring that a parked vehicle’s wheels be chocked to keep it from accidentally moving and hitting someone.

The kicker? The vehicle was a self-guiding hauler and no humans were around to get injured.

The Mine Safety and Health Administration decided a citation was inappropriate, said Matthew Linton, an industry-side attorney with Ogletree Deakins PC in Denver.

In fact, Linton said, it would have been more dangerous to have a worker place blocks against the parked autonomous haulers’ wheels.

“Why on earth would you send a human in?”...