Many cities are developing multiuse urban greenway trails to be used for recreation, exercise, and transportation. Analysts need many kinds of data about these new trails, but especially trail traffic because of its implications for the efficient allocation of resources for trail management. This paper addresses this need by presenting new information about the use of trails. We adapt and test the validity of a previously reported model that predicts hourly pedestrian crosswalk volume from shorter sampling intervals, and we apply the model to greenway trails. Based on 166 hours of data collection on an Indianapolis, Indiana trail system, we develop expansion equations for sampling intervals of five, ten, fifteen, and thirty minutes. We find that both the equations from the previous study and our new equations provide reasonably accurate hourly predictions. Trail managers can use these findings to make decisions about current trail maintenance and promotion.