NTSB Reports on Crash
Involving Pedestrian, Uber Test Vehicle
May 24, 2018
National Transportation Safety Board released Thursday its preliminary
report for the ongoing investigation of a fatal crash involving a
pedestrian and an Uber Technologies, Inc., test vehicle in Tempe,
The modified 2017 Volvo XC90, occupied by one vehicle operator and
operating with a self-driving system in computer control mode, struck a
pedestrian March 18, 2018. The pedestrian suffered fatal injuries, the
vehicle operator was not injured.
The NTSB’s preliminary report, which by its nature does not contain
probable cause, states the pedestrian was dressed in dark clothing, did
not look in the direction of the vehicle until just before impact, and
crossed the road in a section not directly illuminated by lighting.
The pedestrian was
pushing a bicycle that did not have side reflectors and the front and
rear reflectors, along with the forward headlamp, were perpendicular to
the path of the oncoming vehicle. The pedestrian entered the roadway
from a brick median, where signs facing toward the roadway warn
pedestrians to use a crosswalk, which is located 360 feet north of the
Mill Avenue crash site. The report also notes the pedestrian’s
post-accident toxicology test results were positive for methamphetamine
In its report the NTSB said Uber equipped the test vehicle with a
developmental, self-driving system, consisting of forward- and
side-facing cameras, radars, Light Detection and Ranging, navigation
sensors and a computing and data storage unit integrated into the
vehicle. The vehicle was factory equipped with several advanced driver
assistance functions by the original manufacturer Volvo Cars, including
a collision avoidance function with automatic emergency braking as well
as functions for detecting driver alertness and road sign information.
The Volvo functions are disabled only when the test vehicle is operated
in computer control mode.
report states data obtained from the self-driving system shows the
system first registered radar and LIDAR observations of the pedestrian
about six seconds before impact, when the vehicle was traveling 43 mph.
As the vehicle and pedestrian paths converged, the self-driving system
software classified the pedestrian as an unknown object, as a vehicle,
and then as a bicycle with varying expectations of future travel path.
At 1.3 seconds before impact, the self-driving system determined that
emergency braking was needed to mitigate a collision. According to Uber
emergency braking maneuvers are not enabled while the vehicle is under
computer control to reduce the potential for erratic vehicle behavior.
The vehicle operator is relied on to intervene and take action. The
system is not designed to alert the operator.
In the report the NTSB said the self-driving system data showed the
vehicle operator engaged the steering wheel less than a second before
impact and began braking less than a second after impact. The vehicle
operator said in an NTSB interview that she had been monitoring the
self-driving interface and that while her personal and business phones
were in the vehicle neither were in use until after the crash.
All aspects of the self-driving system were operating normally at the
time of the crash, and there were no faults or diagnostic messages.
(This Uber self-driving system data playback from the fatal, March
18, 2018, crash of an Uber Technologies, Inc., test vehicle in Tempe,
Arizona, shows when, at 1.3 seconds before impact, the system determined
emergency braking was needed to mitigate a collision. The yellow bands
depict meters ahead of the vehicle, the orange lines show the center of
mapped travel lanes, the purple area shows the path of the vehicle and
the green line depicts the center of that path.)
The NTSB continues to gather information on the Uber self-driving
system, the vehicle interface, the vehicle operator’s personal and
business cell phones, the vehicle operator, the pedestrian and the
The preliminary report contains no analysis and does not discuss
probable cause. The information in the report is preliminary and subject
to change as the NTSB’s ongoing investigation progresses. As such, no
conclusions about probable cause should be drawn from the information in
the preliminary report.
The preliminary report is available online at