Modeling Merging Behavior at Lane Drops

Project status


Start date: 02/01/13
End date: 01/30/15


Principal investigators:

Student researcher:

  • Nicole Oneyear

About the research

In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improving work-zone flow-through merge points depends on the behavior of individual drivers. By better understanding driver behavior, traffic control plans, work zone policies, and countermeasures can be better targeted to reinforce desirable lane closure merging behavior, leading to both improved safety and work-zone capacity.

The researchers collected data for two work-zone scenarios that included lane drops: one on the Interstate and the other on an urban roadway. Then, these scenarios were modeled and calibrated in Vissim using real-world speeds, travel times, queue lengths, and merging behaviors (percentage of vehicles merging upstream and near the merge point).

Once built and calibrated, strategies for the various countermeasures were modeled in the work zones. The models were then used to test and evaluate how various merging strategies affect safety and operations at the merge areas in these work zones.


Report: Modeling Merging Behavior at Lane Drops (1.65 mb pdf) February 2015

Tech transfer summary: Modeling Merging Behavior at Lane Drops (532.85 kb pdf) Feb 2015



  • Federal Highway Administration
  • Iowa Department of Transportation
  • Smart Work Zone Deployment Initiative