Mega Cities with the Largest Public Transportation Ridership

There are a few interesting research on this matter.  I think Tokyo, Hong Kong and Singapore are leaders in this category!

Public Transport Market Share Trends: 
International Urban Areas from 1980 http://www.publicpurpose.com/ut-...

It is bit old data but public transportation market share the cities should stay somewhat same. Hong Kong, Tokyo, Jakarta, Singapore and Manila are Top 5 cities. 

It is interesting to note the public transportation usage declined average 19%. This must be attributed to 1) suburban sprawl, 2) automotive penetration in developing countries and 3) increase of tele-commutes and self-employed.


Metro systems by annual passenger rides http://en.wikipedia.org/wiki/Met...

1. Tokyo Subway 3.160B
2. Moscow Metro 2.392B
3. Seoul Subway 2.048B
4. Beijing Subway 1.595B
5. New York City Subway 1.579B
6. Paris Métro 1.479B
7. Mexico City Metro 1.414B
8. Hong Kong MTR 1.41B
9. Shanghai Metro 1.3B
10. London Underground 1.065B

PwC's Cities of Opportunity Report-- Public Transportation Index
http://www.pwc.com/en_US/us/citi...
Paris, Chicago, London, Tokyo and Beijing ranked top 5 in Public Transportation sector of Cities of Opportunity report.


Hope it helps!