 The extension of the CTA line in the median of the Kennedy Expressway from Jefferson Park to O'Hare Airport, which included the construction of the Cumberland station, was first proposed by Mayor Richard J. Daley in 1972 by the Chicago Public Works Commission.The cost of this project was initially estimated at $80 million.The Chicago Plan Commission approved the project on August 8, 1974; by this point, the estimated cost of the project had risen to $174 million.