Chicago Transit Authority (CTA) ridership in 2012 grew to its highest annual total in the last 22 years, rising 2.4% to 545.6 million rides for the year, as Mayor Rahm Emanuel and the CTA continued a historic level of investment in the nation’s second-largest bus and rail system.

Ridership performance in 2012 follows an increase of 2.9% in 2011, making this one of the strongest two-year periods in CTA’s history.

Rail ridership for the year increased to its highest level in 50 years, increasing by 9.5 million rides, or 4.2%, to 231.1 million rides. Bus ridership in 2012 increased by 4.05 million rides, or 1.1%, to 314.4 million rides, the third-highest annual total since 1994.

The positive results in ridership come as CTA continues to replace aging railcars with its newest generation of railcars, the 5000 series, and has an aggressive plan under way to replace or overhaul its entire bus fleet.

Ridership has seen some if its sharpest increases during the tenure of Mayor Emanuel. From June 2011-December 2012, ridership rose 4.6%, about 37 million rides, compared to the same time period in 2009-2010.