[Paper Review] Human-Centered Design and Evaluation of a Workplace for the Remote Assistance of Highly Automated Vehicles

Andreas Schrank, Fabian Walocha+2 more|arXiv (Cornell University)|Aug 4, 2023

Human-Automation Interaction and SafetyPsychology34 references3 citations

TL;DR

This paper presents a human-centered design and evaluation of a remote assistance workplace for highly automated vehicles (SAE Level 4), featuring a novel human-machine interface (HMI) tested with 34 professional Technical Supervisors. The HMI enabled high situation awareness and strong usability even under cognitive load, demonstrating feasibility and acceptance for real-world remote operation systems.

ABSTRACT

Remotely operating vehicles utilizes the benefits of vehicle automation when fully automated driving is not yet possible. A human operator ensures safety and availability from afar and supports the vehicle automation when its capabilities are exceeded. The remote operator thus fulfills the legal requirements in Germany as a Technical Supervisor to operate highly automated vehicles at SAE 4. To integrate the remote operator into the automated driving system, a novel user-centered human-machine interface (HMI) for remote assistance workplaces was developed and initially evaluated. The insights gained in this process were incorporated into the design of a workplace prototype for remote assistance. This prototype was now tested in the study reported here by 34 participants meeting the professional background criteria for the role of Technical Supervisor according to the German law by using typical remote assistance scenarios created in a simulation environment. Even under elevated cognitive load induced by simultaneously engaging in a secondary task, participants were able to obtain sufficient situation awareness and quickly resolve the scenarios. The HMI also yielded favorable usability and acceptance ratings. The results of the study inform the iterative workplace development and further research on the remote assistance of highly automated vehicles.

Motivation & Objective

• To design a user-centered remote assistance workplace for highly automated vehicles (SAE Level 4) to support human operators in complex urban environments.
• To evaluate the effectiveness of the HMI prototype in supporting remote operators during realistic, simulated assistance scenarios.
• To assess performance, situation awareness, workload, and usability under varying cognitive load conditions.
• To inform iterative development of remote operation systems by identifying human factors and interface design requirements.
• To support legal and operational integration of remote operators as Technical Supervisors under German regulations.

Proposed method

• Developed a conceptual prototype workplace for remote assistance of highly automated vehicles using human-centered design principles.
• Designed a multimodal HMI integrating visual, auditory, and haptic feedback to support situation awareness and task execution.
• Conducted a controlled simulation study with 34 participants meeting the legal criteria for Technical Supervisors in Germany.
• Induced cognitive load via a dual-task paradigm using 1-back and 2-back n-back tasks during scenario execution.
• Measured performance (task completion time, errors), situation awareness (SART), workload (NASA-TLX), and usability (SUS, UEQ-S, Acceptance Scale).
• Used a within-subjects design with three scenario types (routine, complex, novel) and two cognitive load levels to assess interaction effects.

Experimental results

Research questions

• RQ1 How does the HMI prototype support remote operators in maintaining situation awareness during routine, complex, and novel assistance scenarios?
• RQ2 What is the impact of induced cognitive load on performance, situation awareness, and workload in remote assistance tasks?
• RQ3 How does the HMI perform in terms of usability and user acceptance among professional Technical Supervisors?
• RQ4 To what extent does cognitive load moderate the relationship between scenario complexity and situation awareness?
• RQ5 What are the key usability and acceptance characteristics of the HMI in a realistic simulation environment?

Key findings

• Participants maintained high situation awareness (SART scores in medium to upper range) across all scenario types, even under elevated cognitive load.
• Cognitive load had a negative main effect on perceived situation awareness, particularly during routine tasks, indicating potential degradation under high load.
• The n-back task successfully induced workload, with perceived workload increasing significantly from 1-back to 2-back conditions, confirming the manipulation check.
• The HMI received above-average usability ratings across all three usability scales (SUS, UEQ-S, Acceptance Scale), indicating strong user acceptance.
• Hedonic-emotional aspects of interaction were rated as average-to-positive, suggesting a favorable user experience despite the focus on functional reliability.
• The HMI was well-received by technically experienced participants, with high acceptance scores suggesting potential for adoption by professional Technical Supervisors.