Today, 60 seconds is the deadline managers give each team racing at a dozen stations: to bolt the frame together, lay electronics, add heating and cooling gear, set cushions, and attach trim. Robotic lifting arms help on only one or two steps; handheld tools and elbow grease must do the rest. Each crew is told to clear 680 seats in a 10-hour shift.

That harsh speedup makes it small wonder that repetitive motion injuries are piling up for U.S. auto workers, while the Big 3 auto companies—Ford, General Motors, and Stellantis (formerly Chrysler)—posted $250 billion in profits in just the last four years.