Right-turn-on-a-circular-red traffic signal (RTOR) is a practice which has gained wider acceptance. However, there is still disagreement on whether, where, and how RTOR should be implemented. To determine past experiences with RTOR, a literature review and a survey of state and city practices was conducted. From the results of a questionnaire sent to all 50 states, it was determined that 24 states presently allow RTOR as a general, rule, 22 states permit it with an authorizing sign and 4 states totally prohibit RTOR. The usage of the RTOR provision in those states where it is permitted by sign varies from 0.1 percent to 64 percent of all the state-controlled signalized intersections. City RTOR practices generally follow those of their respective states. The state-of-the-art summary contains information on accidents, delay, capacity, level of service, gap acceptance, and signing. The data collected to date indicates that RTOR does not significantly increase accidents but does reduce right-turn delay.