Rail ridership statistics

Amtrak ridership stats here

From an Amtrak News Release, August 10, 2009:
Amtrak has posted six consecutive years of growth in ridership and revenue, carrying more than 28.7 million passengers in the last fiscal year. Amtrak provides intercity passenger rail service to more than 500 destinations in 46 states on a 21,000-mile route system.

Full release here

See also July 23, 2009 Amtrak to Report Greenhouse Gas Emissions, Independent Review to Assess Carbon Footprint

and June 3, 2009 Amtrak Signs Agreement with Virginia to Provide New Passenger Rail Service