Take a Seat! – Passengers’ Perceived Risk and Driving Behavior Preferences During Automated Driving in Urban Mixed Traffic Depending on the Seating Position

In future urban mixed traffic, passengers of highly automated vehicles (HAVs; SAE Level 4) will observe from a passive position how the automated system resolves space-sharing conflicts with crossing vulnerable road users (VRUs) at junctions. Since passengers are no longer required to intervene in the driving task but can choose any seat in the automated vehicle, we investigated the effects of seating position on passengers' driving behavior preferences and perceived risk in this space-sharing conflict. In a stationary driving simulator study, we varied HAV speed, VRU type, VRU crossing direction, and the passenger’s seating position (driver’s seat, passenger seat). During each VRU interaction, participants triggered the HAV’s braking maneuver by pressing a button, at (a) a point they considered ideal and (b) at the last acceptable braking onset they considered safe enough for the HAV to stop at the stop line. After each trial, participants rated perceived risk on an 8-point scale. We also analyzed the distance of the HAV from the VRU and the time-to-collision with the VRU at braking onset. Data were collected from 30 participants. The results show that seating position has no effect on passengers' perceived risk or on their preferred braking onset timing. Instead, passengers aimed to avoid risk experiences when interacting with the VRU, regardless of the seat position. These results are consistent with previous studies.