Physical inactivity contributes to a growing proportion of illness and premature death in the United States. Only about 45 percent of Americans meet the recommended national standard for physical activity. Yet, analysis of 300 surveys collected from train riders at three walkable New Jersey suburban train stations showed that 78 percent met the activity guidelines. A new train station that allows these riders to save time in their commute has attracted new riders and has led existing commuters to change their commute. One-third of those surveyed reported additional physical activity primarily because they walked more after leaving the train in mid-town New York City. Only 8 percent reported less physical activity. The analysis revealed that the new public transit station and personal factors associated with a greater likelihood of using mass transit led to more physical activity.