Driver fatigue: crashes, the law, and traffic police officers’ experiences and views

• Driver fatigue is underreported in official road crash statistics. • We analyzed the Croatian crash database regarding driver fatigue. • We surveyed 1037 Croatian traffic police officers on driver fatigue. • Fatigue was noted in < 1% of crashes in the national database. • Challenges in recognizing and prosecuting fatigued drivers persist. Driver fatigue has long been recognized as an important cause of road crashes. However, official road crash statistics based on police reports underestimate its prevalence. The enforcement of laws regarding driver fatigue is difficult because no validated and reliable device exists to measure fatigue/sleepiness levels. This study examined driver fatigue in Croatia, focusing on its recognition in law, crash reporting, and enforcement. It aimed to quantify fatigue-related crashes and assess traffic police perspectives on the issue. We used three data sources: (1) national road crash data from 2009 to 2018, (2) a survey of Croatian traffic police officers (n = 1037) using a modified Finnish questionnaire, and (3) Ministry of the Interior records on drivers penalized under article that addresses driver’s fitness to drive including driver fatigue (2013–2023). The results show that driver fatigue was noted in fewer than one percent of crashes recorded in the national database, even for those that resulted in fatality. Punishing drivers based on their fatigue also appears to be rare. These numbers seem understandable considering Croatian traffic police officers’ reports of the difficulties they face in recognizing driver fatigue and prosecuting drivers on that basis. However, traffic police officers are aware of the dangers of driver fatigue. Conclusions. Challenges remain as to how to utilize the traffic police force in the detection of fatigued drivers on roads, recognize the role of fatigue in crash causation, and effectively enforce driver fatigue laws.