Commuters who use the Chicago Transit Authority's Brown and Purple lines to The Loop will need to make alternate travel plans for 18 days during March and April.
The transit agency announced Monday that reconstruction of the 91-year-old Wells Street Bridge over the Chicago River will halt trains for two nine-day periods.
There will be no Brown and Purple line service over the bridge from 10 a.m. on Friday, March 1 through the morning rush on Monday, March 11; and again from 10 p.m. on Friday, April 26 through the morning rush period on Monday, May 6.
Tracks will be replaced during those periods, officials said.
The CTA has posted full details of the service changes -- which include additional bus service, shuttle buses, rerouted trains and a Loop shuttle train -- on its website at TransitChicago.com