Market segmentation has been considered an essential tool for evolving technology to examine for extensive adoption. Flex route transit (FRT) is a personalized transportation mode, which is expected to grow in the future. Therefore, FRT adoption has sparked a significant amount of research curiosity. This study endeavors to examine and identify potential FRT adopters considering attitudinal factors and socioeconomic characteristics by a framework of “perceived benefits–attitude–intention.” To this end, the technology acceptance model and theory of planned behavior are utilized to extract six attitudinal factors. The multiple indicators multiple causes model is employed to capture these attitudinal factors. Robust analytical procedures (e.g., clustering, multiple discriminant analysis, and chi-square test) are implemented to determine the number of clusters and validate the results by a survey in Beijing based on attitudinal factors and socioeconomic characteristics. Results show that potential FRT adopters are segmented into three clusters, that is, “conservatives,”“skeptics,” and “enthusiasts.” Attitudinal factors and socioeconomic characteristics for each cluster are compared and analyzed. A series of implications are recommended to policymakers, which might offer pertinent suggestions to encourage FRT adoption.