The agency is launching an eight-year program to rebuild more than 20 old railroad bridges on the Union Pacific North Line. All the bridges are on the city's North Side.
The entire line will be affected because trains in both directions will have to use a single track at worksites.
Metra says it's going to change arrival and departure times, and some trains will skip certain stops.
The first part of the $185 million program will start in about a month.
A list of proposed schedule changes can be found on Metra's website.