This Diploma Thesis aims to investigate the impact of nighttime driving on driver behavior and safety in urban areas. In order to achieve this objective an experimental process on a driving simulator was carried out, in which all participants drove in different driving scenarios in an urban environment. Regression statistical models were developed to investigate the impact of nighttime driving on the mean speed (lognormal), on the standard deviation of the mean headway distance and on the mean reaction time (linear). Αdditionally, binary logistic method was used to investigate the influence of nighttime driving in the probability of an accident. The models’ application demonstrated that nighttime driving leads to an increase of the mean speed, of the standard deviation of the mean headway distance and of the mean reaction time, resulting thus to a significant increase of the probability of an accident.