Public transit systems play an important role in combating traffic congestion, reducing carbon emissions, and promoting compact, sustainable urban communities. The usability of public transit can be significantly enhanced by providing good traveler information systems. We describe OneBusAway, a set of transit tools focused on providing real-time arrival information for Seattle-area bus riders. We then present results from a survey of OneBusAway users that show a set of important positive outcomes: strongly increased overall satisfaction with public transit, decreased waiting time, increased transit trips per week, increased feelings of safety, and even a health benefit in terms of increased distance walked when using transit. Finally, we discuss the design and policy implications of these results and plans for future research in this area. Author Keywords public transit, real-time information, mobile devices, sustainability, safety, walking, health ACM Classification Keywords H.5....