Report 30413-9949

Date

Jan 2025

Manufacturer

May Mobility

Vehicle

2024 Toyota Sienna

Location

Ann Arbor, MI

Speed

0 mph

Engagement

ADS

Report narrative

What was reported

The May vehicle was involved in a rear-end collision shortly after completing a right-hand turn. As the vehicle proceeded through its turn, it encountered exhaust fumes from vehicles waiting at a stoplight in the adjacent lane. Due to environmental conditions and sensor limitations, the vehicle's lidar system interpreted the exhaust plume as a solid object in its path. In response, the autonomous vehicle first tried to adjust its position. When this maneuver proved insufficient, the system initiated a hard stop response. The vehicle behind, which was following at approximately 7-8 meters, was unable to stop in time and collided with the rear of the autonomous vehicle. The collision occurred at relatively low speeds (the autonomous vehicle had decelerated from approximately 7.6 m/s to 0 m/s), though exact impact speeds of the following vehicle were not recorded. The primary factor that led to this incident is that Lidar does not pierce through exhaust so the exhaust cloud appears to be a large, solid object. Some corrective actions that will be implemented: consider weather implication in future platform sensor selection and continue working on the software to improve a neural network to classify lidar points, which will use temporal information, radar, and camera features to make a decision on whether a lidar point is truly an object.

Crash context

Conditions and outcome

Injury severity alleged

No Injuries Reported

Crash with

Passenger Car

Subject movement

Stopped

Roadway

Street

Weather

Rain

SGO metadata

Report details

Report type

Monthly

Report version

1

Submission date

FEB-2025

Incident time

12:34

Operating entity

May Mobility

Driver / operator type

In-Vehicle and Remote (Commercial / Test)

Within ODD

Yes

Same vehicle ID

4c85884484f99f3

Same incident ID

50b8e1c5db49055