Evaluation of Lane Reduction and Late Merge Signing

• September 8th, 2023

When approaching a lane reduction, drivers typically attempt to merge into the appropriate lane as soon as possible, even in congested conditions. Aggressive driving can occur when drivers merge at the last minute because they are potentially perceived to be “cutting the line.” This perception could stem from traditional traffic control device messaging suggesting that the merging responsibilities differ by lane. For this reason, some transportation agencies have considered or used methods to encourage a late merge at a lane reduction, sometimes referred to as a “zipper merge,” in which drivers are encouraged to remain in their lane until the merge point and then alternate merging into one lane.

Read the full study here.