{'fraction_non_alphanumeric': 0.017272727272727273, 'fraction_numerical': 0.0, 'mean_word_length': 4.951351351351351, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Improvements to Airport Ground Access and Behavior of Multiple Airport System: BART Extension to San Francisco International Airport

Metropolitan regions with more than one major airport—multiple airport systems (MASs)—are important to the U.S. air transport system because of the large number of passengers they serve. Airport ground access factors strongly influence the allocation of traffic in MASs. The effects of improvements to airport ground access (by nonautomobile modes) on airport use in a MAS are analyzed. A case study of an extension of a Bay Area Rapid Transit rail link into the San Francisco International Airport (SFO) is presented. Two airport choice models were developed. One is a nested logit model in which the airport choice decision occurs at the higher level and the mode choice decision at the lower level, and the other is a multinomial logit model. The results indicated that improvements to SFO ground access would modestly strengthen SFO as the dominant airport in the San Francisco Bay Area and that most of the diversion of passengers would be from Oakland Airport.