In monitoring the global development of metro, UITP has collected data on a series of key indicators including ridership, number of lines, stations, and fleet size.

Since the last World Metro Figures in 2018, 14 new cities have opened a metro system, taking the total to 193 cites.

At the time of gathering this data in 2020, global ridership fell by 60% as a result of COVID-19. This ranged from 32% in Asia-Pacific to 63% in North America. While many networks have since recovered a substantial part of the drop in passenger numbers, few have reached 2019 levels.

With all this rich data, here are some of the key highlights into a Statistics Brief, World metro figures 2021, showing the latest data collection from the year.

The Statistics Brief offers a glimpse at the changing times, how metros are developing worldwide, especially as citizens are demanding more sustainable alternatives to private cars.

Seven Asia-Pacific cities are in the top 10 longest metro networks. Since 2018, Chengdu joined the top 10 and jumped straight to fourth place. Guangzhou climbed two positions to No. 5 while Shenzhen went up three positions to No. 7.

"Metros are a unique urban transport mode thanks to their capacity to move unparalleled numbers of travellers efficiently across transport corridors and networks," said Corentin Wauters, rail manager, knowledge & innovation. "UITP provides a detailed picture of the evolution of metros in terms of infrastructure, fleet and ridership – across all regions and throughout an eight-year period. The data shows a sustained development of metro infrastructure, notably in fast-growing cities which face major challenges for mobility and quality of life and also have a role to play in climate change mitigation."