Driving style and driver behaviour are important in evaluating city bus drivers. Buses are one of the means of public transportation in cities, used by millions of people. The purpose of this study was to present a model for preliminary classification of driving style of the professional drivers based on averaged maximum values of lateral and longitudinal acceleration recorded during regular work. First, the recorded acceleration values of 69 city bus drivers were analysed. Then, the correlation between the acceleration values and the age and experience of the city bus drivers was examined. Based on the results of the preliminary classification of drivers, extreme values for both lateral acceleration and longitudinal acceleration (deceleration and acceleration) were obtained by 3 drivers out of the 69 tested. The study also examined the relationship between averaged values of maximum lateral and longitudinal acceleration and driver age and experience. Based on the correlation results, showed that age and the number of years of holding a driver's license are not significantly related to acceleration. Therefore, the method can be used to analyse drivers regardless of their age and experience.