? The book analyzes the efficiency of ?zmir Metro system by using the method of Comparative Benchmarking. It is a good method to measure the efficiency of any system when there is limited and unprovided data. In the theoretical framework, the need and emerge of each transit mode is discussed, and the importance of mass transit concept is pointed out. The concept of "Efficiency" as the quality of well and effective service without wasting time, money or energy is described and the efficiency criteria for public transportation is determined. Efficiency is evaluated from the operator''s point of view. The applications of the method of Comparative Benchmarking in public transport are overviewed. In the case study a virtual benchmarking group is set up among the similar 17 undergrounds worldwide. Specifically, performance measurement stages of the method are applied to indicate the performance of ?zmir Metro compared to the other undergrounds. The participants of this benchmarking group are the undergrounds of the following cities; Ankara, Calcutta, Fukuoka, Helsinki, ?zmir, Kyoto, Los Angeles, Manila, Marseille, Minsk, Nizhni, Novosibirsk, Taipei, Tianjin, Toulouse, Warsaw, Yerevan.