Newswise — It’s called “zipper merge,” and more and more transportation departments around the country are encouraging motorists to use it, according to an Associated Press report by Bill Draper. That’s when a driving lane is closed ahead, and motorists use all available lanes and alternate entry into the open lane when they reach the lane closure. Missouri and Kansas have recently joined Minnesota and Washington in encouraging use of the “zipper merge.”
However, it’s not uncommon for drivers in the open lane to consider it rude when drivers in the closing lane merge at the last moment.
Dwight Hennessy, professor of psychology, is an expert in traffic psychology. He said that Midwesterners tend to be polite and follow the rules—even the unwritten ones. “When a rule is being violated by someone else, it frustrates us, it irritates us, it makes us angry," Hennessy said. “We expect everyone else to follow the rules, and when they don't and we know they're getting an advantage, it ticks us off.”
Hennessy is frequently consulted for his expertise on the emotions of drivers, including road rage.