Autonomous cars may be headed your way and they will be in dialogue. Today, Google’s Waymo vehicles display your personal initials when they arrive at your pickup. But they lack an advance way to communicate more information. That will change and future cars will talk. It’s called a “tertiary language.”  

“Tertiary language” is not a new idea. Historically the term referred to the acquisition of a third dialogue by multilingual speakers (and gifted learners) who had acquired two other languages- say a Japanese speaker who was also proficient in English. Today, the idea is extending to cars. 

Tertiary Language:

In car talk “Tertiary Language” refers to the signaling sent by a driverless vehicle so that humans, whether on foot or in another vehicle, can predict the vehicle’s intentions. “Intentions” is a clumsy way of saying what the vehicle intends to do next, say to slow down or stop. For the time being, the tertiary language will be one-way, from vehicle to human.

There’s a need for this. We are accustomed as drivers and pedestrians to rely on human to human communications for safety. We do this when there’s uncertainty or a blind spot. For example, at some intersections the driver, a pedestrian or a bicyclist signals with their raised hand, an upward glance, or eye-contact. These gestures indicate an awareness of each other, and a protocol for working out who has the right of way. At a four way stop a driver might use a hand signal or the horn, to clarify what goes next. As goes human nature, these gestures can quickly become flippant or offensive.

For the past five years, probably longer, there has been study of how to implement vehicle- to- human speak. The Rand corporation, a think tank/defense consultancy, developed a complex set of guidelines to help cars, pedestrians and bicyclists dialogue.

In the Dome:

Now Waymo, the autonomous driving division of Google, is introducing  a tertiary language to its vehicles. It will start with the LED  dome, which sits on the roof of the vehicle. The LED resembles a modern-day periscope. Pedestrians in front of the vehicle will see shifting gray and white rectangles that  indicate that the vehicle plans to yield to them. Drivers behind the vehicle, will see a yellow pedestrian symbol informing them that there’s a pedestrian crossing. These messages will join chimes, and other alerts. 

For the time being, this “tertiary language” is a one-way language. In the future, pedestrians and bicyclists might carry their own version of a LED or use an app on their phone to signal their presence to vehicles. Although these devices are not on the market yet they might gain acceptability as a way to control the spiraling rate of non-motorized injuries and deaths.

Roadblocks:

For the time being the one-way tertiary language of Waymo vehicles faces two roadblocks . First, Google needs to standardize the “tertiary language.” It would be a virtual Babylon if Cruise, a competing vehicle company, favors an alternative set of colors,  say “blue” to signal “yield.” Likewise,  humans need to become conversant with this new code and recognize the color patterns.

Perhaps the biggest roadblock is getting humans to respect this tertiary language. While it sounds easy, people still choose to crash through the flashing red signals at a railroad crossing or plow through work zones that are set up with cones. Operations of the Cruise autonomous vehicle in San Francisco were suspended when the human employees chose to suppress complete video coverage of an injury accident. Simply put, human communication is complex and it is our nature to want to mislead or outwit machines. The intricacies of human communication are layered deeply, well beyond tertiary.