ITASCA, Ill. — Much to the disappointment of some residents in a number of Chicago suburbs, the U.S. Surface Transportation Board has approved the merger of Canadian Pacific Railway and Kansas City Southern.

The deal is worth billions of dollars and proponents say it will be good for the economy, but opponents have long expressed concerns about what it will do to their communities.

Wednesday’s decision is two years in the making and comes after the board held several local public hearings and reviewed an environmental impact study.

“We made this decision because, in general terms, we found that on balance, the merger of these two railroads will benefit the American economy and be an improvement for all citizens in terms of safety and environment,” board Chairman Marty Oberman said from Washington D.C.

The $31 billion merger will create the largest freight company and run from Canada to Mexico through the United States.

It will impact 54 crossings on 20 miles of Metra’s Milwaukee District West Line, running from Bensenville to Elgin.

Officials said this would triple the number of freight trains each day on the line and the trains will be up to 2 miles long, which could cause delays for drivers and first responders.

Residents also expressed concerns about declining property values.

Metra also spoke out against the merger and said it could cause delays for its passengers.

Canadian Pacific said the merger would free up 64,000 semi-trucks on U.S. roadways each year, with more goods being shipped by train and also decrease greenhouse gas emissions.

But some of those who live and work along the rail line are worried about the quality of life.

“We’re going from at least three freight trains a day to at least 11 freight trains and as many as 18 freight trains a day,” Rep. Raja Krishnamoorthi, D- District 8, said. “According to EIS, 11,000 carloads of hazardous materials will cross through Chicago suburbs, 50% of which are flammable.”

Tracy Daddono, the owner of La Bella Salon and Boutique in Itasca, isn’t happy about the merger. She said her customers and employees will be delayed much more often crossing the tracks.

“We will let our clients know this is something they’re going to try to have to plan for now,” Daddono said.

Community leaders along the rail line have long voiced their concerns about the impact to the quality of life and public safety.

“Our concern is for the police officer caught up in a situation where he or she needs backup and that is delayed by a freight train, the survivability of a citizen who collapses and stops breathing but the ambulance is delayed because of a freight train,” Itasca fire Chief Jack Schneidwind said.