Local, state and railroad officials talked about improvements at a groundbreaking ceremony at tracks south of Wireton Road in Blue Island.
Work will start soon, said William Thompson, program manager for the Chicago Region Environmental and Transportation Efficiency Program.
The program, a major effort to ease rail congestion in the Chicago area, has completed 43 of 78 rail and highway projects planned throughout northeastern Illinois.
About 1,200 freight trains travel through Chicago every day, Thompson said. Of those, about 160 run through Blue Island, Mayor Donald Peloquin said.
The first part of the work is on the railroad bridge over 127th Street, Thompson said. The bridge is already wide enough for a third line, he said. The new third will run from Francisco Avenue northwest to about 123rd Street, Thompson said. The new line will be linked to an existing third line, east of Francisco Avenue, for about six miles in total, Blue Island Peloquin said.
He compared the work to adding a lane to a highway, with the third line allowing "through trains" to roll through the area without having to slow or stop, as is now often the case.
"Now, those trains have to stop two or three times to get a free track. With the third line, they won't have to stop," Peloquin said.
A new signal system will also be installed, helping speed trains along, he said.
Peloquin, whose city has 123 grade crossings, hopes more efficient freight train traffic could improve area truck traffic since a third rail line means trains won't be delayed as often as before.