Transportation for America released a new study on which U.S. cities are most dangerous for pedestrians. If you're going for a stroll in Florida, keep your wits about you: Orlando, Tampa, Miami, and Jacksonville take the top five spots.The report blames most pedestrian deaths on what they call "poorly designed arterial roads"-they're high-speed, multi-lane city streets lined with shopping centers, drive-throughs, apartments, and office space, yet devoid of pedestrian-friendly elements like crosswalks.