A paper titled “Modelling the effect of traffic regimes on safety of urban arterials: the case study of Athens” authored by Athanasios Theofilatos, George Yannis,  John Golias and Eleni Vlahogianni is now published in Journal of Traffic and Transportation Engineering. To achieve the aims of the study, traffic and accident data during the period 2006–2011 from two major arterials in Athens were collected and processed. Firstly, a finite mixture cluster analysis was implemented to classify traffic into clusters. Afterwards, discriminant analysis was carried out in order to correctly assign new cases to the existing regimes by using a training and a testing set. Lastly, Bayesian logistic regression models were developed to investigate the impact of traffic regimes on accident likelihood and severity. The findings of this study suggest that urban traffic can be divided into different regimes by using average traffic occupancy and its standard deviation, measured by nearby upstream and downstream loop detectors. The results revealed potential specific hazardous traffic conditions. In general, high occupancy values increase accident likelihood, but tend to lead slight accidents, while PTWs are more likely to be involved in an accident, when traffic occupancy is high. Transitions from high to low occupancy also increase accident likelihood.