Google has long been a leader in the race toward autonomous cars, and now the company’s self-driving division is setting another precedent.
Waymo—Google’s sister company and driverless auto think tank—is the first to release a voluntary safety report on its self-driving models. The federal government currently encourages automakers to file such information, but does not require it (although that may change soon).
The document condenses 3.5 million test miles and 8 years of work into a 43-page summary, offering a treasure trove of details on everything from Waymo’s testing facilities to its overarching philosophy on the technology.
Submitted to the National Highway Traffic Safety Administration (NHTSA) earlier this month, the report cites another government agency as a source of inspiration: NASA. The document states that Waymo’s approach to vehicle safety was largely modeled off of the processes developed for the Mars Rover—“a self-driving vehicle that operates millions of miles from Earth,” the report notes.
Such space-based influences include testing systems at each and every component level before allowing anything to leave the garage. The process could lead up to “over a hundred separate tests” on a specific camera system alone, due to the different trials designed for individual elements from cables and connectors to camera lenses, the report says.
Software is also put through the testing wringer, the report states, but those experimentations are largely virtual—with Waymo’s computers running thousands of simulations and traveling billions of simulated miles to work out any possible kinks.
The brunt of the testing takes place at a 91-acre closed-course facility in California. Nicknamed “Castle,” it’s specially designed by the company to mimic suburban streets and cityscapes, complete with the full suite of infrastructure, from high-speed roads to railroad crossings to suburban driveways.
All told, the grounds have staged more than 20,000 driving scenarios and recreated situations for the self-driving vehicles to endure, ranging from more common circumstances like aggressive motorists and unpredictable pedestrians to stranger-than-fiction situations featuring “people jumping out of canvas bags or porta potties on the side of the road,” skateboarders lying on their boards, or windswept stacks of paper blowing in front of the vehicles.
The trial runs are important to test not just the set of 28 “behavioral competencies” the government requires of the vehicles (including skills such as detecting and responding to stopped vehicles, navigating turns, and responding to citizens directing traffic), but an additional 19 compentencies developed by Waymo itself—such as detecting and responding to animals, motorcycles, school buses, poor road conditions, unanticipated weather patterns, and faded or missing road signs.
Still, for all the broad expansion of its testing, the company has issued some limitations on its cars. The self-driving vehicles will be restricted by their “operational design domain,” a group of factors roughly sketching out the acceptable conditions of a specific trip.
Among other considerations, the design domain includes “geographies, roadway types, speed range, weather, time of day, and state and local traffic laws and regulations.” Asking a car to operate outside of these considerations will trigger a “geo-fence,” and the vehicles, by design, will not begin their journeys. (If a car is asked to drive outside of an area the company has previously mapped out, for example, or if predicted weather conditions suddenly change, the vehicle will not run.)
Still, Waymo says its ultimate goal is to have cars that “can take someone from A to B, anytime, anywhere, and in all conditions.”
Before they can get there, the company will likely have to go through thousands more tests—and hopefully release a few more progress reports along the way.