Many cities across the U.S. are increasing investment in public transportation in order to reduce greenhouse gas emissions and improve transportation safety. Public transit is getting increasingly expensive, and large transit projects can cost many billions of dollars. To build a more effective transportation system with limited funding, it is important to understand the factors that have the largest effect on ridership. We develop two models to predict public transit ridership per capita for 182 cities based on a number of factors, such as vehicle statistics and funding allocation, from the U.S. Department of Transportation's National Transit Database.