Optimizing Work Zone Zipper Merge Using Federated Driving Simulators

Several Departments of Transportation have implemented the zipper merge to counter the issues of wasted capacity and queue jumping that surface at early merge work zones. This project researched four issues related to zipper merge operations and offered practical suggestions for the deployment of zipper merge. A main result is that public education is vital since many drivers either do not understand zipper merge or are averse to changing from the long-held practice of early merging. Specific recommendations are provided for the deployment of educational materials, including video and written bulletins. Drivers prefer for zipper merge to operate under lower traffic speeds and higher traffic flow conditions. However, simulator results show that zipper merge works even under higher speeds and moderate traffic flow conditions. The placement of the last CMS sign in the zipper merge system near the taper is preferred to produce more desirable driver behavior. This placement can be specified in the MoDOT Engineering Policy Guide. The adoption of these recommendation supported by research could improve zipper merge acceptance and operations in Missouri.