Many of us have been looking forward to the ease of driving on autopilot, freeing up time so we can spend it more productively. After the Tesla Model S, purportedly driving in autopilot mode, crashed into the back of a parked fire truck that was responding to an accident on I-405 in Culver City, Calif., we've come to understand that "autopilot" is apparently not what it seems to be.

Tesla has since released a statement that autopilot is intended only to be used by an attentive driver. But Tesla's autopilot website states, "All Tesla vehicles produced in our factory … have the hardware needed for full self-driving capability at a safety level substantially greater than that of a human driver." The accompanying web video shows that, "The person in the driver's seat is only there for legal reasons. He is not doing anything. The car is driving itself." The website claims "full self-driving capability … enabling full self-driving in almost all circumstances, at what we believe will be a probability of safety at least twice as good as the average human driver." The phrase "almost all circumstances" is critical wording here.

What Does 'Autopilot' Mean?

Greater understanding is needed of the term "autopilot" with respect to vehicles, however. Merriam-Webster defines autopilot as (1) a device for automatically steering ships, aircraft, and spacecraft; also: the automatic control provided by such a device; and (2) automatic pilot. Automatic pilot is defined as a state or condition in which activity or behavior is regulated automatically in a predetermined or instinctive manner, for example, "doing your job on automatic pilot."

By these definitions, and our understanding of the term, we question the use of the term "autopilot" to describe the operations of the Tesla at the time of the crash. What we now know is that a pickup truck suddenly swerved into the right lane to avoid hitting the fire truck, and with the Tesla traveling at 65 mph, there was no time for the driver to react.