Washington, D.C. – On Thursday, the National Transportation Safety Board (NTSB) issued its official report on a November 2017 accident that occurred between a tractor-trailer and a self-driving shuttle bus in Las Vegas.

In it’s report, NTSB places the blame of the accident primarily on the truck driver.

According to the report, a US Foods tractor-trailer was backing into an alley west of South 6th Street while making a delivery just after noon on Wednesday, November 8, 2017.

At the same time, an autonomous shuttle carrying eight people (including one shuttle “attendant”) turned onto South 6th Street headed towards the truck.

The battery-powered shuttle, manufactured by French company Navya Arma and operated by Keolis North America, was tested for 3 weeks in preparation for its deployment into public use, according to NTSB investigators.

According to the report, the day of the accident with the big rig was the driverless shuttle’s first day in public operation.

The autonomous shuttle is not equipped with a steering wheel, accelerator petal, or brake petal.

Instead, it is operated by remote-control, similar to a video game.

Navya says it is possible to control the shuttle remotely from company headquarters in Lyon, France.

However, network time delay would make such an operation unsafe, so it was not performed, according to NTSB.

The shuttle’s on-board sensor system detected the semi-truck ahead at 147.6 feet and tracked it continuously as the truck began backing down the alley.

Reportedly, the shuttle was programmed to stop 9.8 feet away from any obstacle, and the shuttle began to decelerate when it was 98.4 feet from the truck.

However, the shuttle’s attendant, who possessed a class-B CDL and had driven 40-foot motorcoaches for several years, pressed one of the shuttle’s emergency stop buttons, even though the shuttle had almost stopped.

NTSB reports, “the attendant and passengers waved to gain the truck driver’s attention but 11 seconds after the shuttle stopped, the right front tire of the slow-moving truck struck the shuttle.”

The front left of the shuttle collided with the right front tire of the semi. Minor damage was reported to both vehicles.

The Las Vegas Metropolitan Police Department (LVMPD) cited the truck driver on-site for improper backing of a vehicle —specifically, for backing into a one-way, out-only alley.

Employed by US Foods since March 1995, the truck driver told police he made deliveries to that location “two or three times a week.”

In his time delivering to that particular location, he discovered backing into the alley was the “only way … to be safe pulling out.”

NTSB Steps In

Though the collision was minor with nobody injured, the accident was among the first between a fully autonomous vehicle being tested on public roads.

“The NTSB would normally not investigate a minor collision,” Kris Poland, deputy director of the NTSB’s Office of Highway Safety said in a statement released with the report.

“But the involvement of a highly automated vehicle warranted having our investigators examine the circumstances surrounding the collision,” he explained.

The Board released their probable cause on Thursday, which stated the following:

​”NTSB determines that the probable cause of the collision between the truck-tractor and the autonomously operated shuttle in Las Vegas, Nevada, was the truck driver’s action of backing into an alley, and his expectation that the shuttle would stop at a sufficient distance from his vehicle to allow him to complete his backup maneuver. Contributing to the cause of the collision was the attendant’s not being in a position to take manual control of the vehicle in an emergency.”