GM's Cruise Recalls 300 AVs After San Francisco Bus Crash

General Motors' self-driving arm, Cruise LLC is recalling 300 robo-taxis after one of its vehicles crashed into a San Francisco bus on March 23rd.

The relevant documents were submitted to the National Highway Traffic Safety Administration (NHTSA) on Monday, with the Cruise report stipulating that the collision was caused by "an issue related to prediction of the unique movements of articulated vehicles.”

Basically, the test vehicle didn’t understand how a hinged trailer or segmented bus might move and subsequently failed to predict the course of the vehicle it collided with. But we’ve also provided the verbose and technical-sounding jargon provided by Cruise LLC.

From the Equipment Recall Report:

In certain rare circumstances, the Cruise ADS operating with the Subject ADS Software could inaccurately predict the movement of “articulated” vehicles. This issue could occur when (a) the ADS perceived both the front section and rear section of an articulated vehicle initially; (b) the articulated vehicle then maneuvered in such a manner that the rear section of the vehicle fully obstructed the front section of the vehicle; and (c) the articulated vehicle then decelerated close to the AV within a few seconds of the front section becoming obstructed. In such a circumstance, the ADS could inaccurately determine that the obstructed front section of the vehicle was continuing to move forward, and that the rear section of the vehicle would continue to move forward with the front section, even if the vehicle was decelerating.

This issue resulted in a single collision on March 23, 2023, in which a Cruise AV inaccurately predicted the movement of an articulated San Francisco Municipal Transit Authority (“MUNI”) bus. In this incident, the ADS initially perceived both sections of the bus as the bus was pulling out of a bus stop in front of the AV. As the bus proceeded forward into the AV’s lane of travel, the rear section of the bus obstructed the front section. Shortly thereafter, the bus began decelerating. The ADS inaccurately determined that the bus was continuing to move forward in traffic based on the anticipated behavior of the front section of the bus, which was by then obstructed, and the ADS commanded the AV to begin decelerating too late to avoid a rear-end collision with the bus.

Cruise notified the NHTSA the following day and implemented a software update hoping to address the problem a few days later. While we don’t know if this means GM’s autonomous test vehicles can now accurately predict how “articulated” vehicles might maneuver on the road. This is great news for anyone hoping to tow something while Cruise AVs are on the prowl.

This isn’t the first time regulators have been interested in the company for something you would have thought autonomous test vehicles could handle by now. In December, the NHTSA began investigating Cruise’s driving system to uncover why vehicles were being rear-ended after what was alleged to be sudden and unnecessarily hard braking. There were three such incidents reported. However, we’re willing to believe that the whole matter could be attributed to the human drivers tailgating, even if the AVs panicked and stopped harder than anyone had anticipated.

Cruise CEO Kyle Vogt issued an update on the bus collision earlier this week, saying the company had issued a voluntary recall and already updated the software code. He also recounts what happened and attempts to explain why the test vehicle behaved as it did. Vogt then went on to assure readers that the company would be treating the matter with the utmost seriousness and noted that nobody was injured in what constituted a “minor collision.”

“Although we resolved the root cause in this particular incident, our teams continued to investigate the full extent to which this kind of issue occurred in the past, might occur under a variety of conditions in the future, and might be identified sooner,” stated the CEO. “Our vehicles encounter buses like this one every day, but we’d never caused this kind of collision before. We needed to understand if it was more widespread or isolated to a very unique and rare set of initial conditions.”

“Our data and simulations showed that it was exceptionally rare. At the time of the incident, our AVs had driven over 1 million miles in fully driverless mode. We had no other collisions related to this issue, and extensive simulation showed that similar incidents were extremely unlikely to occur at all, even under very similar conditions.”

[Image: Sundry Photography/Shutterstock]

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