Self-Driving Safety Check U.S. Government Data Details 2021 Autonomous Vehicle Crashes

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Animated graphs show statistics for autonomous vehicle collisions.

Data from vehicle makers sheds light — though not much — on the safety of current autonomous and semi-autonomous vehicles.

What’s new: The United States National Highway Traffic Safety Administration (NHTSA) detailed collisions over a 12-month period that involved cars that drive themselves or automate some driving tasks. This is the first edition of what promises to be an annual report.

Going driverless: Fully automated driving systems (often called ADS) that operate without a driver behind the wheel aren’t yet widely available. For the most part, they're being tested in a small number of designated areas. Manufacturers must report incidents that occurred within 30 seconds of engaging an ADS or resulted in property damage or personal injury.

  • Fully autonomous vehicles were involved in 130 reported crashes.
  • Collisions resulted in minor, moderate, or serious injuries in 12 percent of incidents. No fatalities were reported.
  • Most incidents involved other vehicles. A few involved non-motorists or fixed objects.
  • Waymo’s autonomous taxis reported the most incidents (62). Transdev Alternative Services, which makes autonomous buses, trolleys, and other mass-transit vehicles, reported the second-highest number (34). Cruise, which makes autonomous driving systems for Chevrolet, came in third (23).

Extra hands on the wheel: Semi-autonomous vehicles equipped with automated driving assistance systems (known as ADAS) require a flesh-and-blood driver but can steer, accelerate, and decelerate on their own. Manufacturers must report crashes that caused an airbag to inflate, required a car to be towed, or sent someone to a hospital.

  • Semi-autonomous vehicles were involved in 392 reported collisions.
  • Whether injuries occurred and their severity is unknown in 75 percent of cases. Of the remaining 25 percent, injuries were reported in more than half, including six fatalities.
  • The object struck is unknown in 37 percent of cases. The remaining cases divided roughly evenly between other vehicles and poles, trees, and other fixed objects.
  • Tesla vehicles accounted for the most crashes (273). Honda’s semiautonomous vehicles accounted for the second highest number (90). No other manufacturer reported more than 10 incidents.

Yes, but: The report doesn’t tally miles driven by fully autonomous, semi-autonomous, and conventional vehicles, nor at what speeds they traveled. Without that information, there's no way to derive a collision rate per mile or evaluate the severity of injuries at various speeds. Moreover, the report includes only crashes known to manufacturers. It may have missed those that weren’t reported to law enforcement or through consumer complaints. (This may explain the high numbers for Tesla, which harvests data directly from its vehicles.)

Why it matters: Vehicle safety is a life-and-death matter. Fully autonomous cars may not reach the market for years, but a degree of automated driving is commonplace: Vehicles that can steer, accelerate, and decelerate temporarily with a human present accounted for 30 percent of new car sales in the U.S. during the fourth quarter of 2020.

We’re thinking: Initial efforts to collect data, however incomplete, often lead to better data in the future. We hope that NHTSA improves these reports in the coming years by adding the total miles, as well as subdivisions according to in-town and on-highway speed ranges, driven by each of the two automation classes as well as unassisted humans.


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