Traffic and Safety

Zipper Merge Signage Usability Study and Cultural Evaluation

Work zones are a necessary aspect of Minnesota road upkeep, but the reduction in lanes while they are in progress poses a safety threat for drivers and maintenance crews and leads to frustration among drivers. In recent years, Minnesota has engaged in awareness campaigns to educate road users about the necessity of the zipper merge. This encourages drivers to wait until the appropriate time to reduce down lanes before entering a work zone. Some driver, however, report frustration and even aggression toward drivers who abide by the zipper merge feeling unfairness in the practice. Additionally, not all road users understand how the zipper merge should interact with free flowing versus stalled traffic.

This project proposes a usability study examining zipper merge signage. The goal would be to determine if the current signage appropriately conveys the zipper merge message or to determine alternative signage which would establish face validity of the intended meaning of the signs so that extensive education campaigns are not needed. Additionally, the study will measure the cultural attitudes of Minnesota drivers regarding the zipper merge and attempt to shift cultural attitudes through experimental psychological and sociological methods.


Submitted by

Idea Submitted by: Nichole Morris

List your MnDOT Office,District,City, County, Univ. or Other: University of Minnesota, HumanFIRST

Idea Champion - Who at MnDOT/LRRB? : Ken E. Johnson

Project Type - MnDOT or LRRB / Research, Implementation or TRS: MnDOT Research

Stage: Recycle Bin

Feedback Score

6 votes
6 up votes
0 down votes
Voting Disabled

Idea Details

Vote Activity

  1. Upvoted
  2. Upvoted
  3. Upvoted
  4. Upvoted
  5. Upvoted
  6. Upvoted


  1. Status Changed from Active to Recycle Bin
  2. The idea was posted


  1. Comment
    Ken E Johnson

    It would also be worth looking at what may be necessary to help the overall culture change. Signing changes may help, but there may be underlying culture issues that cause some to block traffic from using the legal lane.