Transverse joint spacing is one of the fundamental input parameters in structural design of jointed plain concrete pavement (JPCP). It has to be determined considering many factors to produce a well-performing and cost-effective JPCP. In this study, a comprehensive evaluation of transverse joint spacing in JPCP was carried out based on the followings: (1) guidelines based on previous studies, the Federal Highway Administration and the American Concrete Pavement Association recommendations were summarized; (2) empirical and mechanistic-empirical (M-E) pavement design methodologies were reviewed; (3) current state highway agency practices in USA were surveyed as part of this study and the survey results were documented; (4) effects of joint spacing on JPCP performance were evaluated based on field observations; and (5) lastly, an economic analysis was performed to evaluate effects of joint spacing on life-cycle costs. This study demonstrated that a joint spacing between 15-18 ft (4.6-5.5 m) seems to be provide a safe zone for both performance and cost effectiveness.