The aim of this study is to investigate the unsafe behavior of taxi drivers as a large group of professional drivers and the factors affecting driving violations occurring in Tehran. For this goal, the data regarding driving offenses of urban taxi drivers in 22 districts of Tehran from 2015 to 2016 has been collected from traffic police and used in statistical analysis and multiple regression modeling. According to the results, the probability of a red light violation during working days is more than nonworking days. In addition, taxi drivers older than 70 are more likely to commit red light violation compared to the drivers younger than 30. Moreover, prohibited entry is more probable to occur during working days being about 2.5 times more than that of non-working days. Besides, drivers with newer and more expensive cars commit less driving offenses compared to the drivers with older and cheaper cars. Finally, it was found that by increasing the engine power of the vehicles, the rate of driving offenses by taxi drivers is decreased, such that in cars with 1600 cc engine power or less, the probability of not paying attention to the police regulations is six times more than the cars with 1800 cc engine power and more.