Repair work on a major downtown Chicago bridge has finished its first phase, alleviating headaches for some commuters at least for now.

Chicago Transit Authority officials said Monday that service has resumed on its Brown and Purple lines over the 91-year-old Wells Street Bridge. It was halted for nine days since March 1 as crews worked to replace the southern portion of the bridge that runs over the Chicago River.

A second traffic detour is scheduled for April 26 through May 5. CTA officials will also do track work. Several train lines will be affected, including route changes. The bridge will remain closed to vehicle and pedestrian traffic through late this year.

City officials say the bridge has been in service since 1922.