Abstract. Traffic problems have become a plague of the society that cannot be abolished. This work considers the city of Bangkok and its urban road traffic problem, with a particular focus on traffic light control. Managing traffic control by generating optimal traffic signal timing is one of the solutions to reduce the delay at intersections. Synchro is used as a platform to achieve two things in this work. First, to initialize optimal cycle lengths of the intersections on Sathorn road. Second, to assist in the implementation of reversible lane that involves two traffic signal lights in short distance. All of the data are obtained by the technical team of Sathorn Model project, most of which are based on the field work. A comparative analysis is conducted between optimal cycle lengths and the actual signal timing as operated by traffic police from real data collection to see the improvement of travel times in various cases.