Light rail train: The first subway line was built in the United Kingdom in 1863, and the first tram line was built in the United States in 1888, marking the entry of urban transportation into the rail transit era. After the birth and initial development stage (1863-1924), the shrinking stage (1924-1949), the re-development stage (1949-1969), and the rapid development stage (1970-present), major cities in the world today and megacities have established policies that prioritize public transportation and make rail transit the backbone of public transportation.
