Symbol signs can be more effective than a word message sign if the symbolis easily understood and has adequate legibility. In this study, researchers evaluated driver understanding for multiple alternatives of symbols signs for ten basic message concepts. The concepts were: wireless internet, rental car, ferry, tourist information, automated/photo enforcement, school bus stop ahead, motorcycle warning, truck parking, truck electrification, and Type 3 object marker. Alternatives were developed and refined through a review of international and non-highway symbols, followed by input obtained in focus groups and from an expert panel. The resulting alternative symbol signs were evaluated in a survey that assessed comprehension through three types of questions: open-ended, multiple-choice, and a comparative rating. The results led to recommendations for new symbol signs for seven of the ten concepts. No effective alternative was identified for two of the concepts (rental car and truck electrification) and the existing sign is recommended for retention for one alternative (object marker).
Abstract