Evaluation of Alternative Date Displays for Advance Notification Messages on Portable Changeable Message Signs in Work Zones

In this paper, the results of a laptop-based human factors study of alternative formats of presenting notice of future roadwork messages on portable changeable message signs (PCMSs) in highway work zones are documented. A total of 192 participants across Texas were shown a series of different two-phase messages for a fixed period of time and asked questions by test administrators as a means of determining comprehension and recall of the information presented in each message. Participants were also asked to indicate their preferred format for presenting such information on a PCMS. Based on these studies, the authors recommend that messages that require the display of calendar dates for future roadwork and other traffic control activities should utilize a message format consisting of the three-character abbreviation of the month (e.g., APR for April) in conjunction with the date. When future work activities span several days all in the same month, the month needs to be noted only once in the message (i.e., APR 21-23) rather than repeating the month (i.e., APR 21-APR 23).