On The Legality Of Driverless Vehicles: A Response To Tyler Cowen

I agree with most everything economist Tyler Cowen said in his insightful New York Times op ed about autonomous vehicles. This technology holds tremendous promise in enhancing passenger safety, efficiency, and mobility. (See also Sebastian Thrun’s March 31 TED talk). I also agree that law and policy may act, as Cowen suggests, to impede innovation and adoption of driverless cars. But Cowen’s assertion that the driverless car “is illegal in all 50 states,” which he reasserts and defends in a recent blog post, represents a serious overstatement. And, in a way, an ironic one: the public assertion that driverless cars are illegal could be almost as chilling to potential innovators and consumers as passing laws against this technology.

Cowen’s claim presents a few avenues of objection. The first has to do with my intuition that he did not conduct a fifty state survey. What most people in America mean when they say that something is illegal is that there is a law against it. No one told my wife she cannot drive her car in a housecoat. I’m going to assume she can. Even were I to come across an antiquated California law that says she cannot, we are going to need to look at the laws of forty nine other states and countless municipalities to determine that driving in a housecoat is everywhere illegal. Cowen’s original op ed cites no examples of laws banning driverless vehicles. He follows up in a blog post with one. A vehicle code in Falls Church, Virginia states: “No person shall operate a motor vehicle upon the streets of the city without giving full time and attention to the operation of the vehicle.” Note that not even this one example necessarily means that driverless cars are illegal. If, as Cowen concedes, the Falls Church code was not intended to ban driverless vehicles, why would we read it to do so? After all, no “person” can “operate” a driverless car (or, as I like to call them, “all-passenger vehicle”) by definition. Hence, on one reading, a person riding in a driverless car cannot violate the ordinance. (Remember Fuller's commemorative World War II jeep on display in a park where no vehicles are allowed.) Another quirky California law supposedly holds that “No vehicle without a driver may exceed 60 miles an hour.” This would seem to imply that driverless vehicles may travel up to 60 MPH in this state. Finally, Cowen makes an appeal to pragmatism or optics. Imagine that you were to sit in the backseat of an autonomous vehicle “singing raps songs with your shirt off.” Would not a police officer pull you over? Maybe so. Setting aside for a moment that most commuters would be sitting in the front seat with their shirts on, the question is not whether you get pulled over by a police officer, but whether, upon deliberation, the state upholds the sanction. Police may fail to enforce illegal acts; they may also react to acts that are not illegal. This is one reason we have courts. Whether driverless vehicles are lawful depends on the state of the law and its interpretation. This potentially life- and energy-saving technology will face plenty of obstacles—obstacles that the Stanford Center for Internet and Society and the Center for Automotive Research at Stanford have joined up to study. We should not be eager to claim fifty more. [Image: Stanford CIS Robot Block Party.]


Much as I sympathize with the cause, the politics of approaching self-driving as if it were legal is risky. Should you put a driverless car on the road in, say, New Jersey and be stopped doing it, the potential for a negative public reaction would be high indeed. You would appear reckless and risk the goodwill that such a new technology might have.

The technology might be better served by arguing that it must demonstrate an ability to interact in the range of driving situations (or if you like, with certain carve outs) with certainty and safety not less than that of the average driver, and that it should prove "competence" over time in a graduated roll out.

This is the battlefield which you must control now. The greatest risk is that an antagonist should determine the measure of "legality", which might be a millions of times safer than the average driver. This may prove technically feasible, but difficult to demonstrate and costly to deliver. For an example of a "hostile" standards, consider requirements for nuclear waste disposal at Yucca Mountain. This requires that the site serve as a safe depository for one million years--a very high standard. But wouldn't 100-200 years be enough? And isn't the appropriate standard whether Yucca is safer than storing waste on site, which we know from Fukushima, is a bad idea?

In any event, you need to control the standard, not the law. And the key to controling the standard is to demonstrate concern for safety and competence in managing risk.

Realizing that purchase of beer by a person under the age of 18 is illegal, can I send my dog with some cash to pick up a six-pack at the corner convenience store?

"Another quirky California law supposedly holds that “No vehicle without a driver may exceed 60 miles an hour.” This would seem to imply that driverless vehicles may travel up to 60 MPH in this state."

I love that there is a law that makes it illegal to have a driverless vehicle exceeding 60 miles per hour. What on earth was this put in place to prohibit?

Some of the disconnect in the debate is semantics. As an engineer, the act of sitting in the driver seat monitoring the GUI that displays the autonomous systems state, environmental sensing and tracking status, etc. is 'operating' the vehicle in my book. You may not have your hands on the wheel or feet on the pedals but you can take over direct control in the historical sense at any time based on the status or trends. This is a more likely next step with respect to practical phase-in of fully autonomous vehicles. If there is a law that seems to prohibit this, it probably wasn't written with these vehicles in mind hence we need to educate and communicate more thoroughly and effectively all around.

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