After reading federal motor vehicle safety standards report

This is pretty simple. The law, 49 USC 30111, giving the United States Department of Transportation (USDOT) authority to promulgate regulations governing automobile safety standards does not mention the word "driver." The law simply leaves safety regulation for motor vehicles to the USDOT.

The regulations, however, mention the word "driver"word or allude to a driver quite a bit. And that is what the USDOT report on FMVSS - federal motor vehicle safety standards - is all about. Entitled Review of Federal Motor Vehicle Safety Standards (FMVSS) for Automated Vehicles Identifying potential barriers and challenges for the certification of automated vehicles using existing FMVSS, the report is a catalogue of those regulations. Literally a list of regulations and text.

I'm guessing that none of the USDOT lawyers in any way related to this report was willing to jump out on a big limb and say, "We can promulgate driverless regulations right now." 

Why? That statement would be a big risk: It would piss off some people, including some members of Congress. It could be a rather sizable power grab by the USDOT.

Now, having been trained as a lawyer myself, I can also state that such a move by the USDOT could easily be challenged in court because, let's face it, the law authorizing the regulations was passed when the only thing approaching driverless was the Jetsons cartoon. Or Star Trek. Or something imaginary.

Be creative, you learned this in law school

But there is a way for USDOT to move forward with driverless before Congress acts. Check out this statutory nugget at 49 USC 30114. 

The Secretary of Transportation may exempt a motor vehicle or item of motor vehicle equipment from section 30112(a) of this title on terms the Secretary decides are necessary for research, investigations, demonstrations, training, competitive racing events, show, or display.

See? There's gold in those statutory details.