The seat belt -- the simple lap-belt design -- was not required on cars in the United States until a decade after its invention.
A fail-safe -- a device to stop unintended acceleration in electric cars -- is not required in America now. And Tesla, the electric, self-parking car manufacturer, says it has no duty to make one.
That is the big issue in a proposed class action filed in a California federal court recently. The lawsuit cites 26 incidents in which Tesla cars have suddenly accelerated, including 22 crashes. The plaintiffs allege a design defect, and say Tesla should have created a fail-safe to fix it.