I'll have to try and find the article, this was years ago, but there was a study about people just tapping their brakes lightly that would cause the person behind to do the same, a little longer, etc. etc. that would cause a big traffic jam over time. The study calculated some figure that showed if people just kept their distance up to the person in front, and instead of lightly tapping the brake as a reaction to a merge, and just let the car idle a bit to slowly decelerate, you could reduce traffic slows / jams by a lot. This seems more reasonable than the solutions presented by this article, don't let people merge.. really?