To discourage cars from speeding on the street in front of Ecole Bilingue de la Nouvelle Orléans, a French immersion school in New Orleans, the city has painted nearly 400 polka dots on the pavement. WDSU-TV says the school hired a designer to devise a solution, and the city approved. Some neighbors have objected, but officials say the polka dot strategy has been used in other states and countries where it has helped slow traffic and improve safety.