The TerminaLink system opened on May 24, 1999[6] as a 0.1 mile (0.2 km) line with two stations, connecting Terminal C and Terminal B with a maintenance building for the rail vehicles between the two terminals. The system was funded by Continental Airlines at a cost of US $58 million, and was built to provide easy access between the airline's two airport terminals. Construction was completed in a total of 30 months[7] and was the last phase of Continental's US$200 million airport expansion project.[5]
In 2001, the system was expanded 0.6 mile (0.9 km) from Terminal C to Terminal D.[2] The electrical work for the expansion was supervised by TAG Electric Company who installed over 71 miles (114 km) of cables and wires for the project.[4]
The airport has expanded the line to Terminal A at a cost of US$100 million, and construction began in early 2008 and was completed in 2010.[8]
In 2015, the airport updated its branding. As part of the initiative, TerminaLink and the Inter-terminal Train were renamed to Skyway and Subway, respectively. The new names refer to each APM's location; Skyway is the elevated track, while Subway is underground. This was intended to make it easier for travelers to differentiate the two lines. Skyway vehicles also received blue and green body wraps with the new name.[9]