Tesla Vehicle Safety Report for the fourth quarter of 2020 reveals an interesting trend as the results are, in general, worse than in the past three quarters. It really seems that Q4 has the lowest average distance per accident throughout the year.
A worrying thing is that for the past two quarters the average is also down year-over-year for the two categories with Autopilot disengaged, while the year-over-year improvement when driving on Autopilot is only slight (12.4% recently and 5.8% in Q3).
The company registered:
- Autopilot on: one accident for every 3.45 million miles driven (up 12.4% year-over-year)
- Autopilot off, active safety features on: one accident for every 2.05 million miles driven (down 2.4% year-over-year)
- Autopilot off, active safety features off: one accident for every 1.27 million miles driven (down 22.6% year-over-year)
It's important to note that the results are comparable only for a particular category, not between the categories as the input data might be widely different. In other words, we can only see whether the active safety systems are improving over time (and it's also only a rough comparison), but can't compare Autopilot to non-Autopilot driving.
We assume that the proper use of Autopilot improves safety, but Tesla's report does not allow us to evaluate the difference.
Tesla Safety Report – Q4 2020
"In the 4th quarter, we registered one accident for every 3.45 million miles driven in which drivers had Autopilot engaged. For those driving without Autopilot but with our active safety features, we registered one accident for every 2.05 million miles driven. For those driving without Autopilot and without our active safety features, we registered one accident for every 1.27 million miles driven. By comparison, NHTSA’s most recent data shows that in the United States there is an automobile crash every 484,000 miles.*
*Note: Since we released our last quarterly safety report, NHTSA has released new data, which we’ve referenced in this quarter’s report."
- data for each setting might be collected at different driving scenarios (like simple highway driving or complex city driving), which makes the results incomparable between the categories
- we don't know the methodology of registering accidents
- assuming the methodology was not changed, we can see how each category improves over time
- NHTSA average for the U.S. (updated rarely) includes all cars, also old
- results might be affected by various factors, including seasonality (reduced daylight, weather conditions), less driving during COVID-19 lockdown