Most sprawling cities around the world feature public transit systems that transport millions of passengers every day. These networks are often the life blood of movement, as they connect people to their jobs, homes, and daily livelihoods.
Experts estimate that, across the planet, approximately 60 billion rides using metro networks take place every year. It’s certainly no small thing to say that some of them require huge amount of resources and cover great distances.
So, which systems are the biggest? Click on to find out.