Fell asleep and caused a fatal head-on crash? A case study of multidisciplinary in-depth analysis vs. the court

Recognizing road accidents as sleep/fatigue-related is a challenging task due to the lack of validated criteria and reliable devices (cf. breath analyzer for alcohol levels). Consequently, it is difficult to incorporate fatigue in operationalized terms into either traffic or criminal law. Finnish Road Traffic Act explicitly forbids driving while tired but only on a general level regarding the driver's fitness to drive. The aim was to explore and compare the discussions held and conclusions reached by multidisciplinary accident-investigation teams and Finnish courts.

We describe nine fatal head-on crashes in which, according to the multidisciplinary investigation teams, the guilty nonintoxicated surviving driver had fallen asleep and caused the death of an occupant in the other vehicle.

Despite the obvious difficulties with the data collection, the investigation teams provided sufficient information and explanation as to why falling asleep was the most probable cause of these nine accidents. On the other hand, there was wide variation in the court discussions and decisions. The court extensively deliberated on the role of fatigue in the four cases and only one driver was charged under the article of the Road Traffic Act covering driver fatigue.

In conclusion, this study illustrates difficulties in enforcing the law that forbids driving while tired. Although multidisciplinary investigation teams analyze fatal accidents for safety-research purposes, and have a wider degree of freedom when making their conclusions, we believe that such expert evidence would be beneficial to the courts when they consider similar cases.