The maneuver is known as the late merge — or zipper merge, for the way that cars taking turns getting into a lane resembles the teeth of a zipper coming together. The move, in which drivers in dense, slow-moving traffic remain in the lane that will be closed and then pull into the other lane at the merge point, helps ease congestion and drivers’ frustrations, experts said. In less-dense, free-flowing traffic, there is less need to rely on the late merge, officials said. A driver in a free lane who zipped to the merge point and then tried to cut in could be judged similarly. She was excited to see a zipper merge in action and zoomed to the merge point in the lane that was to end.

Source: New York Times October 12, 2016 15:16 UTC