Service on the JR Chuo Line, one of the key commuter lines in the Tokyo metropolitan area, was disrupted Sunday when an overnight project to switch to new tracks was delayed by eight hours.

According to East Japan Railway Co., operations on the Chuo Line were suspended between Mitaka and Tachikawa in western Tokyo until 1:52 p.m.

A total of 234 train runs, including 24 express trains, were canceled, affecting 180,000 passengers.