NHTSA has drafted a rule that would let self-driving cars use steady cyan lights to show when the automated system is in control. The plan would update Federal Motor Vehicle Safety Standard 108, the federal lighting rule, to cover vehicles like Tesla's Cybercab that arrive without a steering wheel or pedals.

 

The draft would let automakers add optional cyan "ADS marker lamps" that switch on only when nobody is expected to watch the road. Comments on the plan are due 30 days after the notice appears in the Federal Register, before regulators decide whether to finalize anything.