Cell phone service providers will expand coverage to all 47 underground Metro stops within the next few months, according to WMATA spokesperson Dan Stessel.

The Washington Metropolitan Area Transit Authority project called “Neutral Host” has been a two-year-long collaborative effort with the four major U.S. cell carriers — Verizon, AT&T, Sprint Nextel and T-Mobile — to bring better phone service to Metro’s tunnels and stations.

Cell service is currently available in 20 of the system’s biggest underground stations. Rosslyn, Dupont Circle, Metro Center and Smithsonian were among the first stops to receive improvements.

Construction was slowed last fall because it conflicted with necessary upgrades to Metro’s deteriorating rail system, posing the risk that work would not be completed before Congress’ October 2012 deadline.

However, Stessel said that the project is now back on track. According to him, work on the 27 remaining stations is about 75 percent complete.

The District expects to earn about $25 million in revenue from its 15-year contract agreement with the four providers, according to The Washington Post.

The revamp project began in 2008 with federal funding from the Passenger Rail Investment and Improvement Act, which allocated a maximum of $1.5 billion for the project. Cell phone networks were tasked with installing equipment, while WMATA needed to provide safety escorts for the networks’ construction crews.

“Metro’s role [in this project] is to provide access for carriers, help customers track outages and ensure safety and protection,” Stessel said in an interview with The Hoya.