traffic waves

In addition to taking driver's ed, people should be required to take an introductory course on nonlinear fluid dynamics before they're allowed to drive. Especially on freeways at rush hour. Then they might have a clue about how to facilitate merging and changing lanes (such as, not tailgating) without setting up standing waves of traffic that can persist until rush hour traffic subsides.

If they don't take a course on nonlinear fluid dynamics, they should at least read this website.

(Of course, if public transit to the studio in the city where I practice ballroom was more reliable and didn't take three to four times longer than driving, I wouldn't have to be frustrated with traffic at all.)