"S" Curves

For three days I drove around in Oklahoma City trying to figure out what these wavy white lines signified. At one point it occurred to me that they might be some kind of pre-marked sobriety check points. ("Please walk the white line for me, Sir.") However, that idea didn't make much sense. They were clustered together in certain areas and completely absent in others. Besides, the police have all kinds of electronic gadgets to check sobriety these days. Finally, on day number four, the purpose of these wavy lines popped into my head: They mark the beginning and end of school zones. Doh! Fortunately, schools were not in session while I was driving around OKC. (Note: There are also the more traditional signs announcing the beginning and end of school zones.)

"S" Curves