The possible associations between climate parameters and drivers' fatigue have not been subject to specific studies thus far. We have undertaken a study to investigate whether the particular climate parameters are related to fatigue perception by motor vehicle drivers. The study was performed from July to October. Each driver was surveyed four times: before and after workshift on a monotonous route outside the city center (MR), and on a heavy traffic route in the city center (HTR). The study was conducted among 45 city bus drivers aged 31-58 years (43.7 ± 7.9), seniority as driver 3-34 years (14.7 ± 8.6). Data on climate conditions (ambient temperature, air pressure, humidity, wind speed, precipitations) on particular study days was obtained from the Institute of Meteorology and Water Management, National Research Institute Warsaw, Poland. Fatigue was assessed using the Fatigue Assessment Questionnaire, developed at Nofer Institute of Occupational Medicine (Lodz, Poland). The total level of fatigue was significantly (p = 0.045) higher after driving on HTR than on MR. The number of symptoms was also significantly higher (p < 0.05) among drivers working on HTR. After MR, significant correlations were found between wind speed and heavy eyelid feeling, being prone to forgetting, eye strain, frequent blinking, and between ambient temperature and feeling thirsty. After HTR feeling thirsty, tiredness and difficulty in making decisions correlated with ambient temperature and feeling thirsty with wind speed. Climate conditions can modify the drivers fatigue; therefore, we should be aware of their impact on well-being.
Keywords: Bus drivers; Climate conditions; Road accident; Safe driving; Symptoms of fatigue.