At 12:05 EDT, a Piper PA-28-161 struck a parked truck while attempting an emergency landing on a highway north of Lake Wales. The pilot was not injured. The pilot said that the engine began running rough shortly after takeoff and he attempted to land on the highway, where he struck a parked truck. The engine was started at the site and ran at all power settings. The pilot stated that during the emergency he did not apply carburetor heat. Weather conditions were favorable for the formation of carburetor ice at the time of the flight.