Scenario Parameters for Fatigue Induction in Truck-Driving Simulators: A Systematic Review of Experimental Designs

Driving simulators offer a safe and controlled way to study fatigue in truck drivers, but variation in scenario design and incomplete reporting limit reproducibility and cross-study comparison. This systematic review synthesized scenario parameters used in truck-driving simulators to induce fatigue-related reductions in alertness and identified recurring protocol patterns associated with interpretable fatigue-related change. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and a prospectively registered protocol (PROSPERO CRD420261302272), systematic searches were conducted in February 2026 in Scopus, Web of Science, IEEE Xplore, PubMed, and ScienceDirect. Peer-reviewed original studies published in English were eligible if they involved truck drivers, used a driving simulator, reported fatigue-relevant scenario parameters, and measured at least one fatigue-related outcome; no restriction was applied to publication year. Twenty-three studies comprising 419 participants met the eligibility criteria and were synthesized narratively. Risk of bias was appraised using an adapted 11-item checklist for driving simulator experiments, developed with the National Heart, Lung, and Blood Institute (NHLBI) quality assessment tools as a reference framework. Across the qualitative evidence base, fatigue-related change was reported more consistently in protocols combining sustained time on task with low-variability driving demands, typically implemented through monotonous road environments and reduced traffic complexity. Effects were more readily interpretable when sessions were scheduled at night or after work shifts and when outcomes were assessed repeatedly during the drive. However, incomplete control or reporting of baseline sleep pressure, stimulant intake, counterbalancing, familiarization, simulator sickness, and outlier handling limited causal interpretation and confidence in cross-study comparison. Overall, the evidence supports recurring design patterns rather than a single optimal protocol and highlights the need for standardized scenario descriptions and minimum reporting requirements.