Evaluation of flashing traffic signal operation

Operating traffic signals in the flashing mode is a viable alternative to normal (green-yellow-red) operation in many instances. Some of the common applications of flashing traffic signals include: for railroad preemption, in school areas, during low-volume periods, as the result of a signal malfunction, and prior to/following signal installation/removal. This report describes the research results of a two year study on flashing traffic signals. The following activities are described in this report: a literature review of previous flashing signal research, a survey of current practice related to flashing signal operation, an operational analysis comparing flashing signal operation to other types of signal operation, and an investigation of accident trends. The findings from these activities were used to develop a series of guidelines addressing the conditions under which it is appropriate to place traffic signals in flashing operation, and the selection of the flashing mode (yellow/red or red/red).