Elon Musk wants to send a fully autonomous Tesla from Los Angeles to New York by the end of 2017.
But a former government transportation official is skeptical Musk can achieve that.
"I think it is a good goal, I think it is an ambitious goal," said David Kelly, a former NHTSA administrator. "But I don't know if it is a realistic goal."
A Tesla representative was not immediately available for comment.
"We have seen this over and over again that government and government regulation does not move as quickly as innovation in the technology space," said Kelly, now a principal at Storm King Strategies, a government relations firm.
"So one of the things we are going to see is we will see the technology be ready here probably in a couple of years, but we are really talking five, six, seven, maybe even more years before all the regulations come in, before the states play a role in it."
One of the challenges facing autonomous driving is the "patchwork of different regulations and competing authorities" across the country.
NHTSA enforces federal traffic laws and vehicle regulations, but state governments also have authority over licencing and laws within their borders. California has already begun taking steps toward legislation regulating autonomous vehicles on its roadways, he noted.
Kelly also acknowledged Tesla CEO's apparent frustration with some of the media coverage of the company's Autopilot technology on Musk's call with reporters Wednesday, where the CEO blasted critical coverage of Autopilot accidents and contrasted it with the "paucity of media coverage of the 1.2 million people that die every year in manual crashes."
"He is really pushing to be first," Kelly said, "and this is a situation where is is more important to get it right than it is to get it first."