By Tracy Swartz
The Blue Line is the slowest it's been in nearly six years, according to slow zone data posted Monday by CTA.
About 21 percent of Blue Line track is under slow zone, during which trains travel 35 miles per hour or less, CTA data show. This is the highest percentage of Blue Line slow zones since June 2008, when trains traveled slowly on 21.5 percent of track, according to CTA maps.
The CTA announced last year it would begin work this year on easing slow zones on the Blue Line's O'Hare branch, which has about 21 percent of its track under slow zone. The CTA plans to improve track between the Damen and Belmont stations and the Grand and Division stops as part of a $492 million, four-year overhaul.
Six years ago, the CTA tackled the slow zones between Harlem and O'Hare and Jefferson Park and Addison. During that rehab, Blue Line riders endured shuttle buses replacing trains and trains running on single track.
After that project, slow zones dwindled to 3.5 percent in December 2008.
Last year, Blue Line slow zones ranged from 10.8 percent to 19.8 percent.
The Forest Park branch is suffering more than the O'Hare Branch. Nearly 30 percent of that track is under slow zone, as of Monday.
The Illinois Department of Transportation and the CTA held meetings last year on how to improve that section of the Blue Line and expand the neighboring I-290 Expressway.