Part of the O’Hare International Airport expansion has been given the green light. Part of the big goal in expanding O’Hare is to construct runways that are parallel to each other and don’t criss-cross. The airport is the second-busiest in the country, and city officials have said Chicago’s economy would suffer without updating the airport.

Joe Schwieterman is a professor of transportation at DePaul University. He said the $1.17 billion agreement between the federal government, the City of Chicago, and two major airlines could resolve one of the trickiest parts of the expansion on the airport’s south side.

“The city pulled something off here that is pretty impressive,” Schwieterman said. “They got the federal government to ante up, they got the airlines to stand in unison so that critical south runway can move forward. That’s a huge payoff.”

Officials have proposed adding a runway and relocating major roads on the south end of the airport. The parties involved in the expansion say they will negotiate the rest of the modernization plans in two years.