Will Self-Driving Cars Make Roads Safer?

by William Mattar | October 5th, 2017

As outlined in a number of previous entries, the proponents of self-driving cars argue that their widespread use will drastically reduce the number of collisions and, as a result, injuries and deaths resulting from such collisions. A recent study by the RAND organizations casts some doubt on this assumption—or at least posits that such an assumption is premature given the limited data.

The “key findings” of this study are:

• Autonomous vehicles would have to be driven hundreds of millions of miles and sometimes hundreds of billions of miles to demonstrate their reliability in terms of fatalities and injuries.
• Under even aggressive testing assumptions, existing fleets would take tens and sometimes hundreds of years to drive these miles — an impossible proposition if the aim is to demonstrate their performance prior to releasing them on the roads for consumer use.
• Therefore, at least for fatalities and injuries, test-driving alone cannot provide sufficient evidence for demonstrating autonomous vehicle safety.
• Developers of this technology and third-party testers will need to develop innovative methods of demonstrating safety and reliability.
• Even with these methods, it may not be possible to establish with certainty the safety of autonomous vehicles. Uncertainty will remain.
• In parallel to developing new testing methods, it is imperative to develop adaptive regulations that are designed from the outset to evolve with the technology so that society can better harness the benefits and manage the risks of these rapidly evolving and potentially transformative technologies.

In essence, the study finds that self-driving car developers “cannot simply drive their way to safety” by logging miles. They must instead “develop innovative methods of demonstrating safety and reliability.” This necessity is reinforced by the fact that “current traffic fatalities and injuries are rare events compared with vehicle miles traveled.”

A Popular Mechanics article reacts to the study, quoting its coauthor at length:

Americans drive like crazy. We rack up nearly 3 trillion miles every year, according to the Bureau of Transportation Statistics. In 2013, there were 2.3 million injuries reported, a rate of 77 injuries per 100 million miles driven. The 32,719 deaths from car crashes that year correspond to a rate of about one fatality per 100 million miles driven. “Even if you’re not a statistician, you can say: if I want to prove through test driving that autonomous vehicles are safer than humans, I’ve got to drive them at least 100 million miles without a fatality,” [the study coauthor said].

Thus, while Google boasts that its fleet has drive 1.3 million miles without a fatality, there is a rub: “Even if autonomous vehicle fleets are driven 10 million miles, one still would not be able to draw statistical conclusions about safety and reliability.”

So will self-driving cars truly make our roads safer? Is it too early to tell? You decide. Nonetheless, it will be interesting to watch the autonomous vehicle industry’s reaction to the study.

At William Mattar, we offer a free case evaluation if you or someone you know was injured in a car accident. For your free case evaluation, contact one of our Rochester car accident lawyers.