The investigation of geometric indiscipline at urban intersections by optimizing

In the developing countries including Turkey, the unplanned and nonfunctional intersections are being built because of the lack of knowledge and inexperience of planners and decision makers. These intersections, which are not constructed according to a specifications, are unable to provide the necessary service quality and therefore operational and traffic safety problems are observed. These phenomena encourage the drivers to act aggressively without complying the rules, and thus many traffic accidents happen everyday. Unfortunately, in many countries involving Turkey, the traffic authorities willing to plan the intersections with the goal of increasing the intersection capacity rather than ensuring the traffic safety. This attitude leads to the formation of illegal additional lanes in the intersection legs, thus traffic congestion problems and unwilling accidents are observed continuously. In the scope of thesis, the aforementioned problems were identified at the intersections of the pilot city of Antalya/Turkey and HCM 2000, HCM 2010 and Australia (Akçelik) methods which are widely used in the literature were implemented to calculate the delay and queue lengths at intersections. It has been observed that these aforementioned methods, proposed for the developed countries, are insufficient in calculating the delay and queue lengths at signalized intersections of Antalya city due to the lack of evaluating the illegal additional lane formations at intersection legs. To solve mentioned problem, new and modified methods for Turkey have been proposed by modifying these selected methods using Artificial Bee Colony (ABC) optimization method with new parameters (additional lane number, current lane number and platform width). A new program named as DE-INT (Design of Intersections) has been developed in order to design a geometry and prevent complexity for intersection legs by solving existing geometry problems at signalized and unsignalized intersections in Turkey. DE-INT is also has capability of implementing the modified methods proposed in this study for calculating the delays and queue lengths for the selected intersection geometry. For validating the results of the developed program, a micro traffic simulation software Vissim was used as a validation tool. The Vissim traffic analysis results were compared with the proposed computer program. This comparison clearly demonstrated that, the delay results of both programs were deviated as 7.1% and also the difference between the queue lengths was 5.3%. These aforementioned results are direct evidence of DE-INT computer program that analysis the intersections within the acceptable error limits. In addition, it was determined from the analysis for the unsignalized intersections using the DE-INT program that the suggested geometries for the intersection legs reduce the delay times at intersections and increase the traffic safety. The obtained results of the study also were quantitatively answered the outcomes of solving the illegal lane formation problems at intersection legs with respect to the delay and queue lengths.