The postponement means normal train schedules will resume for commuters who have complained about long waits and overcrowded trains.
The 8-year-long bridge project had barely gotten under way, but Metra concedes that a plan to have trains share one track in the construction zone was not working.
Repair work on 22 bridges on Chicago's North Side is on hold for now.
A Metra spokesperson says the agency got more complaints about this project than any other in their history.
"The construction in general has been bad, because you've had to switch back and forth on platforms a lot on short notice," said Natalie Leibovitz.
The agency had hoped to do the bridge repair quickly by moving all the trains to a single track for portions of the route, which would have saved about $80 million. They have now decided the complaints outweigh the possible savings.
"The schedule's been the same for so long, and to change it without a lot of notice, it throws a lot of people's schedules off," said commuter Veronica Hill. "It was an inconvenience."
There are more than two dozen bridges on the city's North Side, and most of them are about a hundred years old. Most need to be rebuilt.
Metra has budgeted nearly $200 million for the project, and when finished, the bridges should be good for another hundred years.
Finishing, however, will take several years longer, because Metra is scrapping the plan for now.
Metra had put out several revised schedules for the North Line in the last couple months to accommodate construction, using just one track instead of two. In some cases, that meant half the number of trains during peak travel periods. Commuters complained in record numbers.
"This is kind of messing up my schedule now, so I have to leave later," said Barbara Brass, who takes the train to work at a doctor's office.
"It got to a point where we realized, just the constraint of going to one track the pressure there was far too great to accommodate all of the communities on the line and the inconvenience was far too significant," said Metra spokesperson Judy Pardonnet.
The Metra Union Pacific North Line goes from Ogilvie Transportation Center in the West Loop through the city's North Side and up the North Shore, all the way to Kenosha, Wisconsin. A return to the old schedule is welcome news for many riders.
"Any time you can respond to complaints of your customers, you're going to be better off," said commuter Wes Baumann.
Metra plans to announce a new construction schedule in a few months. They say they will likely stretch the project from 8 years to, possibly, 12.
In the meantime, they say the bridges are safe, but they will have engineers check them routinely to make sure.