In the aftermath of the September 11, 2001, terrorist attacks, the transit industry emerged as a leader in leveraging the value and power of the public's “eyes and ears” to promote system security. Although a public awareness program is widely viewed as a core component of a transit agency’s system security plan, efforts to assess whether the messages are reaching transit riders and to identify obstacles to participation have been limited. This paper highlights strategies and tactics to engage transit riders in public security awareness programs based on interviews with transit agency representatives, the analysis of transit rider survey data, and transit rider focus groups.