Beyond Detection: A Systematic Review of Driver Passive Fatigue Prevention and Mitigation Strategies

Driver fatigue remains a major cause of road crashes, with passive fatigue becoming more critical in automated vehicles. This systematic review evaluates strategies that prevent or mitigate passive fatigue during driving. Following PRISMA guidelines, 34 empirical studies were analyzed to classify interventions by mechanism and timing. Countermeasures were grouped into vehicle-related, driver-based, combined vehicle-driver, and road-based categories. Strategies ranged from auditory cues and thermal stimuli to caffeine intake and conversational agents. Some interventions required active participation, while others worked passively. Effectiveness was often short-term and varied by approach. Measurement methods included subjective ratings like the Karolinska Sleepiness Scale and objective indicators such as eye closure and lane deviation. Most studies focused on passenger cars, leaving a gap in research for commercial drivers. The findings highlight the need for proactive systems that promote engagement and sustain alertness.