were later removed and scrapped during World War II. A 'sample' monorail line was built in Houston in 1955; the Trailblazer operated over a line at Arrowhead Park with a peak speed of , starting on February 18, 1956. The monorail ceased operation in September of that year and subsequently was moved to Fair Park in Dallas for the Texas State Fair, where it continued to run until 1964. False starts Rapid Transit Lines, the successor to HCSR and Houston Electric, proposed a rapid transit system as a long-range project under the 1971 "Transit Action Program" (TAP), developed by Alan M. Voorhees and Associates, largely laid out along the radial spokes centered in the Inner Loop, tracing the city's major freeways. TAP would be implemented in two stages. In Stage 1, of rapid transit routes would be built, including fixed rail lines serving the southwest, west, and northeast parts of Houston (with a downtown subway), and three bus-exclusive lanes along the North, Gulf, and South freeways. Stage 1 was planned to complete in the 1970s at an estimated cost of $800 million. Under Stage 2, scheduled for completion before 1990, the Stage 1 rail lines would be extended and two more would be added, bringing the total system to . TAP would have been the technical basis for the proposed Houston Area Rapid Transit Authority (HARTA), but a referendum to form HARTA was "soundly defeated" in 1973. The city of Houston purchased Rapid Transit Lines in April 1974 for $5.3 million and renamed it the Houston Transit System ("HouTran"). Houston formed the Office of Public Transportation in January 1975 to plan the region's public transportation system, and began working on an update of TAP. After METRO was formed in 1978/79, an initial Phase I alternatives analysis identified multiple potential transit corridors, and under Phase II, proposed in 1980, the "Southwest/Westpark" corridor (along what is now the Westpark Tollway) was prioritized for further study. The proposed Southwest/Westpark corridor would have run , generally parallel to the Southwest Freeway, with equal lengths west and east of the West Inner Loop. The planned route would run from downtown Houston along Main Street to approximately Elgin, and west from Elgin to West Belt along existing public and rail rights-of-way. Service options that could be operated along the corridor included a dedicated busway on an elevated structure (carrying 203,500 daily riders at an estimated capital