Auto safety regulators in the United States are letting Tesla off the hook in connection with the fatal crash in Florida last May.

Last week, the U.S. National Highway Traffic and Safety Administration (NHTSA) concluded its months-long investigation of the fatal crash with a report that the agency found no defects in Tesla’s Automatic Emergency Braking (AEB) and Autopilot systems.

Definitely, Tesla is exonerated.

Did NHTSA let Tesla off the hook too easily? Absolutely.

What lessons or guidance, if any, did NHTSA’s findings offer to the rest of the automotive industry? Very little.

It’s important to point out that nobody is saying that NHTSA didn’t do a thorough investigation. It did. NHTSA’s report, however, exposed limitations in the scope of their probe. The investigation revealed the difficulties regulators face in dealing with highly software-dependent automated driving systems.

Further, problematic was the tardiness of the investigation. Tesla was able to move much faster than the regulator to fix some of the problems (if not all of them) via over the air (OTA) software updates. That’s a good thing, but it rendered the NHTSA probe less than remarkable.

After reading the report, Mike Demler, senior analyst at The Linley Group, complained that NHTSA “largely just matched up the parameters of the incident with the information Tesla provides in owner’s manuals, along with cockpit warnings.”

NHTSA calls the report issued Thursday “ODI (Office of Defects Investigation) Resume.” A defect is an imperfection, or a weakness, noted Demler. But in his opinion, he sees little evidence that government agency actually focused on the weaknesses within Tesla’s Model S at the time of the accident.

NHTSA ODI resume (cr) Figure 1: ODI Resume (Source: NHTSA)

“The critical issue here is that the Tesla fatality involved the combination of AEB and Autopilot,” said Demler. As the report shows, NHTSA “already accepts that AEB reduces accidents, and that the Tesla AEB performed according to the current state-of-the-art,” he explained. “But what happens when you combine AEB with Autopilot?”

He noted, “It would be different if Autopilot just added lane-centring to Adaptive Cruise Control (ACC) and AEB. [If that’s the case], Autopilot’s primary function isn’t safety, but it’s convenience.”

Crossing path collisions: outside the scope?

Baffling to some industry analysts is NHTSA’s assessment of Tesla’s AEB system. The report says: ODI (the Office of Defects Investigation)’s analysis of Tesla’s AEB system finds that 1) the system is designed to avoid or mitigate rear-end collisions; 2) the system’s capabilities are in-line with industry state of the art for AEB performance through MY 2016; and 3) braking for crossing path collisions, such as that present in the Florida fatal crash, are outside the expected performance capabilities of the system.

But hang on. Was that fairly important ODI finding, that “braking for crossing path collisions… are outside the expected performance capabilities of the system,” well understood by Tesla drivers?

 
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