The effect of urban design on traffic safety

Although using the motor vehicles does not have a very old past, urban mobility has increased day by day with the effect of the increasing urban population and expansion of urban spaces, this situation has revealed traffic safety as an important problem in cities. Many factors have an effect on the creation / improvement of traffic safety. One of these factors is urban design. Although urban design was generally considered as a means of organizing urban aesthetics in the first half of the 20th century, today it is accepted as a concept in which the principles of improving the life qualities in cities. Such as, creating a sustainable urban environment, giving cities an identity and originality, ensuring easy access and circulation in an equal and safe manner, and increasing the sense of social belongings in the city. In this study, it is aimed to reveal the effects of urban design applications on traffic safety to benefit policy makers, decision makers and implementers. In this study, urban design principles for transportation are determined firstly, and then a survey is carried out in Turkey and Iran to determine the effects of these policies in road users and traffic safety experts. While Tunali Hilmi Avenue in Turkey is elected as the study area, Zanjan-Deljoi Street, which has similar features in Iran is also selected and surveys are applied to road users in these areas. The data which belongs to road users in both countries are analyzed statistically with the SPSS program, Analytical Hierarchy. Process (AHP) method was used in the study with experts. In this study, the relationship between urban design and traffic safety, through Iran and Turkey are evaluated comparatively. First, urban design principles, components and applications regarding traffic safety were identified. Second, important factors of urban design components relative to each other were calculated via analytical hierarchy process (AHP) method. In addition, surveys were conducted both in Turkey and Iran in order to reveal the relationship between traffic safety and urban design with regard to both road users' and experts' viewpoint. The study fields in both countries were majorly similar, Ankara-Tunalı Hilmi street in Turkey and Zenjan-Deljoi street in Iran. Datas, collected via the survey, were statistically analyzed using Statistical Package for the Social Sciences (SPSS). Results were assessed comparatively among data collected from both Turkey and Iran. Survey results suggest that the most important factor, elevating traffic safety according to traffic users of both countries, is urban design (%34)ç. The next important factors are the drivers', pedestrians' and passengers' dispositions towards traffic safety (%23,3). Moreover, AHP results indicated the most significant factors across two countries within the following criteria: (i) psychical substructure, (ii) speed management, (iii) pedestrian transportation, (iv) bicycle transportation and (v) public transportation. These are (i) platform and lane width in Turkey vs. vertical traffic signs in Iran, (ii) speed limits in both countries, (iii) pedestrian signalization in Turkey vs. pedestrianization in Iran, (iv) separated bicycle roads in Turkey vs. bicycle signalization in Iran and (v) access convenience of public transportation stations in both countries.