Google
has taught its self-driving cars to recognize cyclists and how they behave to better predict their course.

The self-driving car, using sensors and software, can also detect and interpret cyclists’ hand signals, Google says in a report released Tuesday. The self-driving cars have learned to be more cautious around cyclists as a result. The cars have also learned how to recognize different types of bikes such as tandems and unicycles.



Our cars recognize cyclists as unique users of the road, and are taught to drive conservatively around them (it helps to have a number of avid cyclists on our engineering team!).

Through observing cyclists on the roads and private test track, we’ve taught our software to recognize some common riding behaviors, helping our car better predict a cyclist’s course. Our sensors can detect a cyclist’s hand signals as an indication of an intention to make a turn or shift over. Cyclists often make hand signals far in advance of a turn, and our software is designed to remember previous signals from a rider so it can better anticipate a rider’s turn down the road. Because our cars can see 360 degrees, we’re more aware of cyclists on the road—even in the dark.

Prototype
Google introduced the prototype—a gumdrop-shaped vehicle it designed itself—in June 2015. The self-driving car doesn’t have pedals or a steering wheel, but only sensors and software. It hopes to commercialize its technology by 2020. The company’s tests still include Lexus RX450h SUVs equipped with autonomous software. Google is testing its self-driving cars—which are equipped with a backup steering wheel and brakes when on public roads—in Mountain View, Calif., Austin, Phoenix, and Kirkland, Wash.



Get Data Sheet, Fortune’s technology newsletter. If Google hopes to launch its self-driving cars for public use in just four years, its software will have to learn all of the nuances required for driving. For instance, the company recently shared how its engineers taught its autonomous prototypes when it’s appropriate to honk, and to use a different honks and beeps depending on the circumstance. Of course, it needs to be able to see the cyclists too. 



Google relies on sensors as well as light-sensitive radar (known as Lidar), which are large and expensive. Tesla’s autopilot technology, which allows for hands-free driving on highways, does not use Lidar. Tesla CEO Elon Musk has previously called it unnecessary and overkill for what autopilot needs. But that could change.
Concerns surrounding the safety of autonomous vehicle technology—and the continued fallout over the death of a Tesla driver using autopilot—could prompt Tesla and other companies to use Lidar as autonomous features continue to increase in cars.

Chrysler
As our Chrysler Pacifica minivan readies to make a left turn through a four-way intersection in Mountain View, California, it suddenly pauses. Across the intersection, a pickup truck creeps forward with ambiguous intent. Will it proceed? Make a right turn? Is the driver lost? Finally the truck drifts toward the curb, then comes to a stop. The hazard lights begin to blink. The Pacifica makes the turn.Our Pacifica drives deliberately, cautiously, following the law to the letter. It drives the way you yourself probably did during your driver’s license exam. In the back seat, Dmitri Dolgov, Waymo’s chief technology officer and VP of engineering, an intense man of 40 whose speech bears a faint trace of his native Russia, looks perfectly calm. Waymo’s self-driving cars, after all, have now navigated some ten million miles in 25 cities.



Which is extraordinary, considering how murky the world of traffic can be.Dolgov, whose own Waymo car ferried him to work today, as it does most days, has been with the company from the beginning, back when it was known as Google’s self-driving car project. Two years ago, Google spun Waymo out into an independent company dedicated to developing and commercializing self-driving technology, though it hasn’t strayed far from its roots; it still shares its Mountain View headquarters with X, Google’s “moonshot factory.” And it has been the industry leader ever since it grew out of Stanford University’s experimental vehicle, nicknamed “Junior,” which took second place in DARPA’s 2007 Urban Challenge. That race was legendary for how disastrously the primitive autonomous vehicles of the country’s leading roboticists traversed the Mojave Desert. Back then, simple “geometric reasoning”—being able to stay in a lane—was a massive achievement.