Behavioral Science Can Increase Zipper Merge Usage

Research demonstrates that zipper merges (or late merges) are safer and faster than a traditional early merge under heavy traffic conditions. However, in implementation, zipper merges can be less efficient due to a lack of compliance on the part of drivers, who tend to be more accustomed to early merging. Behavioral science has been applied to a many transportation-related challenges, such as increasing seat belt usage and decreasing drinking and driving, but has not yet been applied to the zipper merge. Based on the literature, the researchers have identified seven behavioral science concepts to leverage in zipper merge communications including (1) instructions, (2) information, (3) social norms, (4) appeals to reason, (5) emotional appeals, (6) humor, and (7) activators. To evaluate the prevalence of these concepts, they reviewed existing physical sign and online communications from U.S. state Departments of Transportation. Across the 16 states currently using zipper merges, instructional signs and appeals to reason were most frequently employed. More research is needed to determine the effectiveness of using behaviorally informed communications to increase zipper merge compliance.