When signs or other traffic control devices are used, it is essential that drivers understand the message and know how to take action appropriate to the situation. Failures in sign comprehension could increase driving hazards. The present research investigated comprehension for several types of speed management signs including animal presence warnings involving a flashing beacon, regulatory and advisory warnings, and variable speed limit signs with text and animation. The goal of this study was to determine if people make any problematic inferences from these types of signs. There were 103 participants in this research study. Participants viewed the signs, described what the signs meant, and then completed a comprehension task in which statements about each sign were presented and participants indicated whether the statement was true of the sign. The results from the comprehension task are described in this paper. Findings indicated that: (1) many participants failed to recognize that a hazard may still exist when the beacon attached to the animal presence sign is off, (2) many people thought that an advisory speed on a warning sign is an enforceable, legal speed limit, and (3) the variable speed limit sign was understood with either a text message or with animation. The most critical problem found in this study involved the animal presence signs. Further research is recommended to study better techniques to communicate the dynamic nature of the animal hazard to drivers.
Abstract