NHTSA orders Tesla to prove its Cybercab is legal to sell, under oath

Without the standards it would be difficult to hold automakers liable for defects in design or workmanship, so the standards are more useful as a means to hold automakers responsible for safety failings than they are at internal developing the optimal safe design.

The more specific they get, the more difficult it is for automakers to implement new safety technologies. For example, the safety standards were too specific about headlight design, so we ended up making headlights extremely bright all of the time in the US, for years after other countries were using adaptive headlights that dim in areas with lights and other vehicles, and brighten in dark areas.