Luckily there were no injuries or fatalities to the seven passengers and one attendant in the November 8, 2017 Las Vegas self-driving shuttle service vehicle and a commercial truck. And though it was calculated to be a minor collision, the National Transportation Safety Board (NTSB) was prompted to launch a probe because an autonomous vehicle (AV) was involved. It has now completed its investigation into the incident which was released in its NTSB Accident Brief 19/06.
The NTSB wanted to look at the process of introducing AVs onto public roads and also the role of the company (operator), the vehicle manufacturer and the city.
The Las Vegas autonomous shuttle service vehicle got into theminor accidentjust an hour after it began its year long trial and although the investigation proved that the local government’s claim that the truck driver didn’t stop when it was supposed to, the investigation also revealed another probable cause.
The truck driver, whose responsibility it was to stop, assumed that the AV would stop in time at a reasonable distance. It didn’t. The truck driver did see the the AV seem to slow down, but here’s where the catch is.
The AV has built into its system to begin slowing down when another vehicle is approaching it at 98.4 feet away, however it’s not programed to stop until it’s 9.8 feet away from obstacles. At 10.2 feet the attendant in the AV shuttle service hit the emergency stop button but it obviously was not soon enough to prevent the accident.
During the investigation, the attendant told investigators that they thought of switching to the manual mode in order to move the shuttle out of the way of the truck, but they did not have easy access to the hand held controller device. Even though the Las Vegas AV shuttle service operates on predetermined routes making it easier on the automated systems, the attendants in the AVs can still use a controller in order to use the horn and switch to manual operation in unexpected situations such as what occurred in 2017. However, at that time, the controller was stored in a separate location at one end of the passenger compartment.
Following the accident the shuttle service company has made it a requirement for all attendants to remove the controller out of the storage compartment at the beginning of each trip and to keep it near and accessible at all times.