Community colleges were established as affordable postsecondary education opportunities for all residents within their local areas. Typical measures of access to postsecondary institutions use binary indicators based on the presence of institutions within geographic areas or straight-line distance between student residences and college locations as the underlying metric and implicitly assume that students travel by private vehicles. These factors likely overestimate access within urban areas where relatively large proportions of residents may commute primarily by public transit. In this paper we estimate access based on travel times to community colleges in ten large U.S. cities utilizing public transportation, examine variations in access across those cities, and compare these estimates to distance-based measures of access. We find that access to community colleges based on public transit travel times varies substantially within and across cities and is influenced by each city's geography and built environment. We conclude with a discussion of how measuring college access by travel time reveals the existence of urban community college access deserts.