While you may think letting the person next to you cut in early is the polite way to act on the road, you’re actually contributing to the traffic problem. According to experts, in order to keep the flow of cars moving smoothly, people must use the “Zipper Merge,” which is more efficient. Drivers should instead be encouraged to merge late, with vehicles flowing in like the “teeth” on a zipper. Officials at the Colorado Department of Transportation note that the method can reduce delays up to 40 percent. Back in 2011, Minnesota put up billboards to teach drivers on how to merge properly, says Wired. What do other drivers do that annoys you?

More about: