Progress can be a scary thing. What was once an entertaining if not futuristic concept on automobile travel and personal transportation, the 'self-driving' cars currently being tested in a handful of markets by Google and others has rapidly moved closer to reality.

So much so, that the federal government's National Highway Traffic Safety Administration (NHTSA) was compelled last week to put its foot down and state that self-driving vehicles are not ready for use by the public.

NHTSA says it does not recommend that states authorize the operation of self-driving vehicles "for purposes other than testing at this time." And Edmunds reports that it is discouraging states from even setting up rules governing self-driving cars.

Is NHTSA putting its head in the sand?

"We believe there are a number of technological issues as well as human performance issues that must be addressed before self-driving vehicles can be made widely available," said the federal policy statement, which was posted on the NHTSA Web site. "Self-driving vehicle technology is not yet at the stage of sophistication or demonstrated safety capability that it should be authorized for use by members of the public for general driving purposes."

It added: "NHTSA does not recommend that states attempt to establish safety standards for self-driving vehicle technologies, which are in the early stages of development."

If a state does permit the "non-testing operation of self-driving vehicles," the operator should have a special license.

Such a separate license should have certain prerequisites, including passage of a test concerning the safe operation of a self-driving vehicle, NHTSA said.

It also is recommending that fully autonomous vehicles be equipped with a simple button located within the driver's reach that would enable the human to override the automated system and quickly retake control of the vehicle, if necessary.

The feds also want self-driving vehicles to have the capability of recording malfunctions, "degradations" or failures. States should also insist that the vehicle owner turns over "all data recorded by the vehicle's event data recorder in the event of a crash."

Federal safety regulators issued the policy recommendations because they said "some states are anxious for guidance on how to proceed with regard to self-driving vehicles." Self-driving cars are now legal in California and Nevada. Both states require the cars to have a human behind the wheel who can take control of the vehicle at any time. Google is the most high-profile company working on autonomous vehicles.

Federal safety regulators say we are on the brink of a "historic turning point for automotive travel."

"Motor vehicles and drivers' relationships with them are likely to change significantly in the next 10 to 20 years, perhaps more than they have changed in the last 100 years," the NHTSA policy report said.

Edmunds noted: The feds clearly want to control any rules and regulations governing the use of self-driving cars, urging the states to take a backseat in this matter.

Should the federal government wrestle control of self-driving vehicles from state DOTs? Perhaps that might benefit from closer examination.