Transportation remains a vexing concern in cities that offer students school choice. Time and again, research has shown that families typically want high-performing schools or schools with unique academic programs. But those schools tend to be concentrated in a city's affluent neighborhoods, often long distances from low-income households and students of color. Parents' choices are constrained by how their children can get to school and how long it will take. A choice system can't truly be equitable if the best schools aren't accessible to many students. Many cities--particularly larger ones--have public transportation systems that, in theory, could help connect students to their desired schools. Indeed, cities with robust public transportation networks, such as New York and Washington, D.C., already use their public transit systems to transport students. But in many cities, the transit systems are designed to transport workers to the city's economic centers (usually downtown), while schools are located in residential neighborhoods. So transit networks designed for workers can't always help students get to school. And they can't always connect students from low-income households and students of color to the city's highest-performing schools, which tend to be concentrated in affluent neighborhoods. To better understand these challenges and how they might be surmounted, we analyzed how one city, Denver, approaches its transportation challenges. The authors found that for all students to have reasonable access to a high-performing school, the city will have to look beyond the transit system for solutions. Because of difficult-to-reach neighborhoods, economically, racially, and ethnically segregated communities, and a supply of high-performing schools that remain concentrated in a few regions, many Denver students do not have reasonable access to the city's best schools, and wouldn't--even with free access to public transit. To provide all students with the best opportunities for learning, Denver, and other cities as well, must make strategic investments in improving the distribution of quality schools and will likely have to consider creative solutions like building enrollment partnerships with neighboring school districts, developing micro schools, or providing more students with virtual access to classrooms in the city's best schools.