 Complete the following phrase:  Following the world bobsleigh championships of 1969, 1973, and 1978, many race officials of those championships would serve on the organizing committee for the bobsleigh part of the 1980 Winter Olympics. In 1978 actual construction took place during September 1978-February 1979 with the creation of a reinforced concrete, artificially refrigerated bobsleigh track. The bobsleigh track was approved for competition in December 1979. In fall 1977, a separate luge track for the 1980 Games, the first one in the United States, was constructed with completion in time for the test competition in February 1979. During preparations for the 1980 Games, a combined two-man bobsleigh and luge track was considered, but abandoned to high cost and the track was redesigned with permission from the International Luge Federation FIL. Following the 1980 games, both tracks hosted their respective 