Nearly 17 percent of CTA track is under slow zones this month, which is the slowest the rail system has been in nearly five years.
The slow-zone snapshot for February shows 16.7 percent of the rail system is under slow zones, which is when a train travels 35 mph or slower. The last time the CTA saw a percentage that high was in March 2008, when the CTA logged 16.9 percent slow zones.
"The slow zone percentage is a dynamic number," CTA spokesman Brian Steele said. "As we repair slow zones, other slow zones can occur."
Slow zones are plaguing every rail line except the Yellow and Orange Lines, but some routes are worse off than others.
The southern portion of the Red Line has highest percentage of slow zones, 40.4 percent. The CTA will shut down this section of the Red Line, from Cermak-Chinatown to 95th Street, from May through October to overhaul track and eradicate slow zones.
"We've done a significant amount of slow zone repairs over two years on that line," Steele said.
The rest of the Red Line isn't faring much better. About 17 percent of track in the State Street subway is under slow zones while 20 percent of North Side track has these zones.
Brown and Purple Line riders have also endured slow trains. Slow zones are plaguing 34.4 percent of Purple Line express track and 28.4 percent of Purple Line track north of Howard Street.
Meanwhile, 22.4 percent of Brown Line track is under slow zones.
Brown and Purple Line riders will see some relief this spring after the CTA shuts down a portion of the Brown and Purple Lines near the Loop so the Chicago Department of Transportation can repair the Wells Street Bridge.
During the CDOT project, the CTA will ease slow zones near Hubbard Street. Other repairs to the Brown Line will occur after the project.Want more? Discuss this article and others on RedEye's Facebook page.