A full stoplight requires a full stop which defeats a lot of the benefits of a proper zipper merge where traffic just keeps flowing with no stops. In a more ge

A full stoplight requires a full stop which defeats a lot of the benefits of a proper zipper merge where traffic just keeps flowing with no stops. In a more general sense on a highway any time a car comes to a full stop you have the chance to create a phantom traffic jam as the stop travels back along the incoming stream of cars. https://static1.squarespace.com/static/5005afd7e4b0a6953320bf3f/t/57c6ceb69de4bb8747981006/1472646990392/?format=750w https://static1.squarespace.com/static/5005afd7e4b0a6953320b...