Slow zones on the Chicago L
From Wikipedia, the free encyclopedia
Slow zones on the Chicago L are a recurrent problem. Slow zones are places of track where trains have to run at reduced speeds due to one or more reasons, such as bad track quality, structural issues (e.g. fouling of the ballast,[1][2][3][4] damage to and failure of concrete retaining walls,[5][6] rotting of wooden ties[3]), signal issues,[3] insufficient power,[3] and construction occurring near the tracks. As of March 2026, slow zones covered a total of 210,222 ft (64,076 m), or 17.7% of the entire system.[7]
As of March 2026, outside the Loop, the Pink Line is the only line on the Chicago "L" system without any slow zones.[7]
When the CTA first began publishing slow zone reports in July 2005, there were 108,360 ft (33,030 m) of slow zones on the system, representing about 8.5% of the system.[8] By 2019, the amount of slow zones had climbed to 153,970 ft (46,930 m), or about 13.1% percent of the entire system.[9] As a result of the 2023 Chicago train crash, the Yellow Line was put under slow zones, adding 35,156 ft (10,716 m) to the system. By February 2025, slow zones had reached a total of 351,542 ft (107,150 m), with over 30% of the entire system being slow zones.[10][11]
In April 2025, slow zones on the Yellow Line were removed, and just a month later in May, slow zones had decreased to 212,547 ft (64,784 m), or 18.5% of the entire system. Slow zones continued to decrease into 2026 with March 2026 seeing just 210,222 ft (64,076 m) of slow zones, the lowest amount since October 2023.[7]
