Public mass transit systems are part of the everyday landscape of most major cities around the world. From the ultra-efficient train network of the Tokyo Metropolitan Area to the congested rail lines of Sao Paulo, metro systems move millions of people daily, making inter-city mobility more efficient and reducing travel times within cities and metropolitan regions. Sao Paulo Metro. Source: US News Since the opening of the first underground network in London in 1863, more than 200 metro systems have been built around the world. Beijing currently has the largest metro network in terms of length and daily ridership (807 km in length and 10.5 million trips per day). Other major metro systems are located in New York, Shanghai, Seoul, Moscow and Guangzhou. Despite the accelerated construction of metro systems since the mid-20th century, there are large urban areas in the world that are not currently served by metro services. Some of them have implemented alternative systems such as BRT (Bus R