Abstract
With SAE Level 4 and above (L4+) Automated Driving Systems (ADSs) being integrated on roadways, stakeholders worldwide are developing external communication systems for other road users to communicate effectively. Most research on SAE L4+ ADS external communication has used simulators or virtual reality platforms to assess driver/road user knowledge, opinions, and attitudes via survey metrics evaluating a single L4 vehicle. However, it is vital to understand perception of external communication in real-world conditions and with multiple SAE L4+ ADSs present. This research explored how the presence of multiple SAE L4+ ADSs with external communication displays affected participants’ crossing decisions. A within-subject design assessed participants’ understanding of SAE L4+ ADS intentions. Results indicated that the presence and condition of external human-machine interfaces (eHMIs) did not influence willingness to cross. It was difficult for participants to focus on the eHMI when multiple vehicles competed for their attention. Participants typically focused on the vehicle that was nearest and most detrimental to their crossing path. Scenario type caused participants to make more cautious crossing decisions but did not influence willingness to cross. This study implies that eHMI with two patterns may still require simplification for pedestrians to interpret in a complicated traffic environment.
Project Highlights
- These results have implications for future design of external communication displays on L4+ AVs. Training may be necessary for road users, given the relatively low percentage of participants who understood the meaning of these displays after multiple exposures and participants’ confusion in where to look and how to interpret the intention of the display when multiple vehicles were present.
Final Report
EWD & T2 Products
Student Impact Statement(pdf): Five students received funding and/or worked on this project (Alexandria Rossi Alvarez, a PhD student in Cognitive Engineering, Industrial Systems Engineering from VT and four Undergraduate students in Industrial and Systems Engineering at Virginia Tech: Eli Pritchardd, Josh Kruse, Luke Van Hout, and May Schulte). This file contains a statement by Alexandria Rossi Alvarez as to the impact this project had on her education and workforce development.
A Class module was created discussing this project for an undergraduate and graduate level Human Factors in Transportation course. Slides can be found here.
Presentations/Publications
Rossi-Alvarez, A., Klauer, K., Schaudt, A., & Doerzaph, Z., (2022). Allusion 2: External Communication for SAE L4 Vehicles. Toyota Research Center, Presentation.
Rossi-Alvarez, A., Klauer, K., Schaudt, A., & Doerzaph, Z., (2022). Allusion 2: External Communication for SAE L4 Vehicles. HFES at Virginia Tech, Presentation.
Rossi-Alvarez, A., Klauer, K., Schaudt, A., & Doerzaph, Z., (2023). Allusion 2: External Communication for SAE L4 Vehicles. TRB Conference, Presentation.
Rossi-Alvarez, A., Klauer, K., Schaudt, A., & Doerzaph, Z., (2023). Allusion 2: External Communication for SAE L4 Vehicles. GM Monthly, Presentation.
Final Dataset
The final datasets for this project will be located in the Safe-D Collection on the VTTI Dataverse here.
Research Investigators (PI*)
Charlie Klauer (VT-VTTI)*
Andy Schaudt (VT-VTTI)*
Alexandria Rossi Alvarez (VT-VTTI)*
Project Information
Start Date: 2021-10-01
End Date: 2023-05-31
Status: Complete
Grant Number: 69A3551747115
Total Funding: $207,744
Source Organization: Safe-D National UTC
Project Number: 06-007
Safe-D Theme Areas
Automated Vehicles
Transportation as a Service
Safe-D Application Areas
Vehicle Technology
Vulnerable Users
More Information
Sponsor Organization
Office of the Assistant Secretary for Research and Technology
University Transportation Centers Program
Department of Transportation
Washington, DC 20590 United States
Performing Organization
Virginia Polytechnic Institute and State University
Virginia Tech Transportation Institute
3500 Transportation Research Plaza
Blacksburg, Virginia 24061
USA