, Former Senior Research Associate, College of Design
This was the third study in a series examining the effectiveness of Changeable Message Signs (CMSs). The goal of the study was to investigate the type of dual-phase CMSs that might be used on the approach to an airport. Whereas previous studies investigated static CMSs, this study compared the effectiveness of the dual-phase message with static messages conveying the same information. Participants from three age groups were assigned to two groups. Using a fully interactive PC-based STISIM driving simulator, after driving ten miles on a freeway, one group encountered a dual-phase CMS, while the other group encountered two static (i.e., unchanging) signs. The participants used the information provided by the CMSs to select the correct exit for their airport terminal destination. This research determined the effectiveness of the dual-phase CMS and static signs in providing airport information for drivers on state highways, and whether or not participants slowed down as they approach the test signs. There were no statistically significant differences between the number of participants who failed to take the correct exit in the dual-phase and the static CMS conditions nor were there differences in the number or magnitude of the speed reductions for the dual-phase and static CMS conditions. In this experiment, displaying airline information on a single dual-phase CMS was determined to be as effective in influencing driving behavior as displaying the same airline information on two static CMSs.