It's only 8 miles of track, but the lack of it affects thousands of commuters in the city and suburbs daily.
Union Pacific Railroad and Metra broke ground on a project Friday to create three seamless tracks on the UP West Line, eliminating two troublesome bottlenecks, including a stretch between Geneva and West Chicago.
Adding a third track there, and one from River Forest to Melrose Park, should decrease freight and commuter time delays and congestion, giving the railroad more flexibility in cases of mechanical problems or collisions.
"It will also reduce the wait times and idle times for freight, and motorist wait times at grade crossings," Cook County Board President Toni Preckwinkle said at a groundbreaking event for the project.
The western track addition covers 6.1 miles, running from Kress Road in West Chicago to Peck Road in Geneva, and will take 19 months; work on the eastern segment starts soon and is scheduled for completion in a year. That 1.8-mile section of track stretches from just east of the Des Plaines River in River Forest to 25th Avenue in Melrose Park.
Costs of the $100 million project will be shared by both railroads.
It also gives Metra more scope to increase service or add express trains, although officials weren't making any commitments.
"Our goal is to add additional express service," Metra CEO Don Orseno said. "I'm not saying specifically on the UP but it's one of the things we will be discussing with UP -- how can we increase service ... what better service can we have?"
Ultimately, the project could bring more passengers onto the UP West Line.
"If you've got a faster travel time that's consistent, people will park their cars and get on the train," Orseno said.
The line, which stretches from downtown Chicago to Elburn, carries 60 commuter trains and more than 50 freights each weekday.
UP President Lance Fritz said 25 percent of freight traffic in the U.S. travels to and through Chicago. The new track is the latest in recent improvements UP has instituted on its lines in Chicago. Others include installing warnings at stations telling people if another train is coming.