Every weekday at a rock quarry northwest of Dallas, autonomous dump trucks roll down a dirt road and load up at the bottom of a 140-foot-deep mining pit. The trucks then drive a mile and a half to a rock crusher, where they lift their beds, drop the rocks, then turn around, heading back to the pit for the next load. The work is monotonous, repetitive and—because it involves huge quantities of heavy objects—potentially dangerous. That makes it a perfect job for a robot, says Anthony Levandowski, ...