When you're driving down the highway, the dashed lines that separate lanes appear to be about two or three feet long. They're actually 10, at least according to an article in Science Daily.
The journal Perception & Psychophysic has published a study on misperceptions of drivers led by Dennis Shaffer, an assistant professor of psychology at Ohio State University's Mansfield campus. More than 400 college students were tested, each asked to give their estimate of how long the lines are. Overwhelmingly, they said two feet.
"People cover more ground than they think in a given period of time, so they are probably underestimating their speed," Shaffer says.