This report presents a study whose objective is to explore how people deal with unexpected congestion during the pre-trip stage and how they might respond to Advanced Traveler Information Systems (ATIS). Travelers' route, departure time and mode selection decisions were investigated through a survey of San Francisco Bay Area automobile commuters. The effects of various factors are examined, such as sources of congestion information, trip characteristics, and route attributes. The pre-trip response to future ATIS technologies is explored through stated preferences.
