Objective: The purpose of this study is to provide an overview of the prevalence of driving under the influence of alcohol (DUI) according to day of the week, specific roads (urban/rural), daytime or nighttime, and vehicle category. In addition, this study examines how the prohibition of selling alcoholic drinks in shops and supermarkets (not in restaurants) after 10 p.m. has affected the prevalence of DUI. Method: Breath alcohol concentration (BrAC) was collected from all drivers through police checkpoints at 54 locations in Serbia. In this study, 17,945 drivers were tested in urban areas and 19,507 in rural areas. The relationship between DUI during the prohibition on alcohol sales in Belgrade and other large cities in Serbia was determined using logistic regression. Results: On average, every 100th driver in traffic in Serbia was DUI (0.99%). This study shows that the 0 blood alcohol concentration (BAC) limit for motorcyclists does not have an influence on DUI. Moreover, motorcyclists represent the category with the highest share of DUI, with a statistically significantly larger difference compared to drivers of other vehicle categories. These results may be a consequence of the fact that a large number of drivers drive both motorcycles and other vehicle categories (cars or mopeds), so the different BAC limits for nonprofessional drivers may create confusion about the legal BAC limit. Conclusions: This study suggests that the required legal BAC limit for nonprofessional drivers should be the same. The prohibition of selling alcoholic drinks in Belgrade after 10 p.m. does not decrease the prevalence of DUI.

Inappropriate or unsafe speed is one of the main factors that affects the number of road crashes as well as the severity of the consequences. Research shows that speed is an influential factor in the occurrence of road crashes in more than 30% of road crashes with fatal outcomes and in over 12% of all road crashes. With an increase in speed, the risk of road crashes increases as well as the severity of the consequences. The perception of the vehicle speed in the traffic lane is one of the basic prerequisites for the safe functioning of traffic, that is, for the successful and timely interaction of all road users. Therefore, the challenge of this paper is to examine how the assessment of the speed of a passenger vehicle in different environments affects the prediction of the respondent’s participation in road crashes. Bearing the above in mind, an experimental study was carried out, in real traffic conditions (RTC) as well as in a virtual environment using a driving simulator (DS), at different passenger vehicle speeds (30, 50 and 70 km/h), and at different perspectives of observing the oncoming vehicle (observing the vehicle from the front, from the back, from the side and from the driver’s seat) by the respondents. The respondents had the task of evaluating the passenger vehicle speed, in all tested conditions and at all tested speeds. Standard statistical models and fuzzy logic were used to analyze the obtained results. The results show statistically significant differences for all tested situations and all tested speeds as well as statistically significant differences depending on the gender of the respondents, the driver’s license category, the driver’s experience, frequency of driving and depending on whether respondents wear glasses. Bearing in mind the results of the developed model, by applying fuzzy logic, it can be concluded that the proposed model can be used to assess the propensity of respondents to participate in road crashes, based on perception of vehicle speeds in two tested environments.

Objective: Powered 2-wheeled motor vehicles (PTWs) are one of the most vulnerable categories of road users. Bearing that fact in mind, we have researched the effects of individual and environmental factors on the severity and type of injuries of PTW users. The aim was to recognize the circumstances that cause these accidents and take some preventive actions that would improve the level of road safety for PTWs. Methods: In the period from 2001 to 2010, an analysis of 139 road accidents involving PTWs was made by the Faculty of Transport and Traffic Engineering in Belgrade. The effects of both individual (age, gender, etc.) and environmental factors (place of an accident, time of day, etc.) on the cause of accidents and severity and type of injuries of PTWs are reported in this article. Analyses of these effects were conducted using logistic regression, chi-square tests, and Pearson's correlation. Results: Factors such as categories of road users, pavement conditions, place of accident, age, and time of day have a statistically significant effect on PTW injuries, whereas other factors (gender, road type; that is, straight or curvy) do not. The article also defines the interdependence of the occurrence of particular injuries at certain speeds. The results show that if PTW users died of a head injury, these were usually concurrent with chest injuries, injuries to internal organs, and limb injuries. Conclusions: It has been shown that there is a high degree of influence of individual factors on the occurrence of accidents involving 2-wheelers (PTWs/bicycles) but with no statistically significant relation. Establishing the existence of such conditionalities enables identifying and defining factors that have an impact on the occurrence of traffic accidents involving bicyclists or PTWs. Such a link between individual factors and the occurrence of accidents makes it possible for system managers to take appropriate actions aimed at certain categories of 2-wheelers in order to reduce casualties in a particular area. The analysis showed that most of the road factors do not have a statistically significant effect on either category of 2-wheeler. Namely, the logistic regression analysis showed that there is a statistically significant effect of the place of accident on the occurrence of accidents involving bicyclists.

Vehicle color coatings have long been recognized as a factor influencing road safety, particularly regarding their impact on speed perception and crash risk. This study aims to examine how different vehicle color coatings affect drivers’ perception of speed under nighttime driving conditions, with a specific focus on sustainability and visibility. A controlled laboratory experiment was conducted using a driving simulator to replicate realistic night traffic scenarios. A total of 161 participants evaluated passenger vehicles in four distinct color treatments, white (high-reflective paint), yellow (matte safety film), blue (glossy metallic finish), and black (low-reflective coating), at two speeds: 30 km/h and 50 km/h. Participants’ perceived speeds were collected and analyzed using standardized statistical methods. Results indicated a consistent pattern: speed was overestimated at 30 km/h and underestimated at 50 km/h across all vehicle colors. Lighter-colored vehicles (white and yellow) were perceived as moving faster than darker-colored vehicles (blue and black), with significant differences between black and yellow (30 km/h), yellow and blue (30 km/h), and black and white (50 km/h). Additionally, female participants tended to estimate higher speeds than male participants across most conditions. Other individual factors, such as place of residence, driver’s license type, driving experience, and frequency of driving, also showed measurable effects on speed perception. By using a simulator and accounting for diverse demographic characteristics, the study highlights how perceptual biases related to vehicle color can influence driver behavior. These findings emphasize the importance of considering vehicle color in traffic safety strategies, including driver education, vehicle design, and policy development aimed at reducing crash risk.