As Austin was quickly outgrowing the old Robert Mueller Municipal Airport, the city began considering options for a new airport as early as 1971, when the Federal Aviation Administration proposed that Austin and San Antonio build a joint regional airport. That idea was rejected, as few Austinites supported driving halfway to San Antonio on Interstate 35 to catch a flight. Afterwards, the city submitted a proposal to the United States Air Force for joint use of Bergstrom Air Force Base in 1976. The Air Force rejected the proposal in 1978 as being too disruptive to its operations.