A study of traffic sign symbols was completed recently at the fhwa turner-fairbank highway research center in mclean, virginia. As part of this research, four work zone traffic control warning signs (pavement width transition, flagger ahead, low shoulder, and uneven pavement) were selected for redesign. Several alternatives for each sign were testedin a laboratory experiment. Legibility distance, comprehension, and preference data were collected for each alternative.The results of the study indicate that the current symbolic designsfor pavement width transition and flagger ahead are superior to thealternatives tested and should be retained. The current symbolic sign for low shoulders was found to be inadequate (22 percent comprehension), but an acceptable alternative was not found. Given the infrequent use of this sign and the difficulty of communicating this concept to the driver, the use of the alphabetic low shoulder sign is recommended. For the uneven pavement sign, an improved symbolic designwas identified and is recommended. This paper appears in transportation research record no. 1213, Human performance and highway visibility: design, safety, and methods.
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