Drowsy driving, vulnerable times of the day and traffic accidents

• Main Authors: Lucia Tvarožková, Kamila Kaniová, Robert Zůvala, Petra Labodová, Kateřina Bucsuházy
• Format: Article
• Language: ces
• Published: University of Ostrava 2017-11-01
• Series: Psychology and its Contexts
• Subjects: fatigue; performance levels; vulnerable times of the day; traffic accidents; indepth accident analysis
• Online Access: http://psychkont.osu.cz/fulltext/2017/2017_2_7_Tvarozkova.pdf

It is estimated that sleep-related traffic accidents represent 20 % of all crashes and 25 % of all those with fatal consequences (Engleman & Douglas, 2005; Jackson et al., 2011). There are several risk factors increasing the likelihood of fatigue driving such as driving under monotonous conditions (especially after night shift), lack of sleep or poor sleep, or driving under the influence of certain addictive substances, such as alcohol or drugs. An important factor in determining driver sleepiness is a circadian rhythm, which affects changes in mental and physical performance throughout the day. Therefore, the connection between performance level in a particular time of the day and traffic accident frequency becomes the subject of research. For purpose of this study, the curve of expected human performance (by Kohoutek & Štěpaník, 2000) was used to compare the levels of alertness and the number of traffic accidents in particular times of the day. The aim of this study was to analyse vulnerable times of the day related to traffic accident frequency, based on results from In-depth Accident Analysis in South Moravian Region. Another objective was to determine the extent of correspondence between identified vulnerable times of the day related to traffic accident frequency and the performance curve, describing the expected levels in human performance during the day. Different groups of drivers in terms of sociodemographic factors (gender, age) and driving experience were compared. Data were collected over the project Czech In-depth Accident Study via interviewing road traffic accident participants directly after the accident by a psychologist. The research sample consisted of 213 drivers (149 males and 64 females) who have caused the accident due to their inattention and were assumed to have an average level of vigilance at the time of accident. The data were processed by the statistical software SPSS. A traffic accident frequency curve showed a similar trend as the curve of expected human performance level in the time between 9:00–18:00, where a negative correlation was found (9.00 to 12.00, rp = - 0.76, 12.00 to 15.00, rp = - 0.85, 15.00 - 18.00, rp = - 0.91). For all ages, the most vulnerable time of the day, where traffic accidents happen in a connection with a lower level of expected performance capacity, proved to be time between 15:00–16:00. The least amount of traffic accidents occurred between 10:00–11:00, which represents the time with a higher expected performance level. The increased accident frequency in the early morning hours may be explained by the decrease in drivers´ alertness after waking up. The conclusions of this study partially support results of previous research and the reliability of expected performance level curve during the day (by Kohoutek & Štěpaník, 2000) in a relation to driving. It opens new areas in the field of driver education, how to lead drivers to be more sensitive to their mental and bodily limits, particularly in a connection to their attention level.