Analysis of design methods for signalized roundabouts

In the first quarter of the 21st century, transportation has become a major problem in every country with the developing world structure. This situation is felt more in Turkey, where the general transportation strategy is mostly highways. There are still deficiencies in traffic engineering practices in our country and new solutions are being produced. Although the roundabout application is quite common in the world, it is very weak in terms of signaling technique. In recent years, some studies have been carried out on this subject. In this thesis, "Çakıcı and Murat Method", "Yang Method" and "Akçelik Method", which are among the studies mentioned, were used, various scenarios were created and analyzed with the "VISSIM" simulation program. Scenarios were recalculated with the "Delay Formula for Akçelik" and compared with simulation delay values. As a result of the comparison, the closeness of the delay values was determined and the usability of the Akçelik Delay Formula was proven at roundabouts. Thus, promising results have been obtained regarding the applicability of the "Australia (Akçelik) Method", which is used for signal calculation of at-grade intersections in the literature, for roundabout signal calculation. In the analyses, for different scenarios, an increase in delay times was observed with the increase in volume values for all three methods discussed. It has been found that changes in parameters such as diameter of roundabout, number of lanes, selection of cycle diagram, number of phases, green time and cycle time have positive or negative effects on delay times.