Designing Graceful Degradation for Multimodal Autonomous Vehicle Cabins

Abstract

Future autonomous vehicle cabins may function as immersive spaces in which riders rest, work, or watch media while the vehicle manages navigation and control. Hazards create a communication challenge because riders may have little awareness about road conditions when the cabin needs to convey risk. We examine graceful degradation as a design lens for coordinating multimodal cabin responses across changing hazard states. We conducted a storyboard-based study with N = 12 participants who reviewed three scenarios with different time profiles: a gradual snowstorm, an intermediate pedestrian event, and a sudden incoming vehicle. Participants reflected on staged visual, auditory, and haptic cues. They associated graceful responses with cue strength that tracked hazard tempo, visible system intent, restrained haptics, and a prompt return to the baseline cabin state after danger passed. We position graceful degradation as a temporal interaction framework for rider-facing Level 5 autonomous vehicle cabins. We also identify design tensions and next-step studies around escalation thresholds, haptic intensity, sensory load, trust, and emergency cue offset.