In January, bus ridership decreased 2.2 percent while rail ridership decreased 1.5 percent compared to January 2012, according to a ridership report posted Wednesday on CTA's Web site. System ridership was down 1.9 percent to 41.9 million riders.
The CTA saw systemwide ridership growth 10 out of 12 months last year. The CTA blamed the January decrease on strong ridership gains in January 2012 and warm temperatures that month.
"Warm weather generally brings out more riders," CTA spokeswoman Tammy Chase said. "We don't believe decrowding had any effect on this."
January was the first full month since the CTA instituted its decrowding plan in December. The agency cut more than a dozen full or partial bus routes and added service to 48 bus routes and all rail lines except the Pink and Yellow lines.
January was also the month that saw a rise in the cost of daily, weekly and monthly unlimited CTA passes.
The Red Line took some of the biggest ridership hits. The southern section of the Red Line saw its average daily ridership drop 7.3 percent in January compared to January 2012.
Starting May 19, the CTA is shutting down this section of the Red Line for five months to overhaul the track. About 40 percent of this section of the Red Line is under slow zone.
January is the second straight month of ridership declines. December 2012 also saw a 1.8 percent systemwide ridership decline compared to December 2011.
The CTA pointed out that rail ridership in January was up 7.3 percent compared to January 2011.