ABSTRACT. This study develops an optimization model for bus transit network based on road network and zonal ODM (Origin Destination Matrix). The source information has been obtained via recorded phone data of transit users collected by an Italian telecommunication operator.The model aims at achieving minimum bus transfers and maximum passenger flow per unit length with line length and non-linear rate as constraints. An operations research algorithm is used to solve the problem (ACS). To further optimize results, the model uses Google APIs for traffic optimization. The model is tested with survey data of Rome city. The results show that an optimized bus network with less transfers and travel time can be obtained, and the application of operations research algorithm effectively increases the calculation speed and quality.