Is it legal to drive with fog lights on?
In the United States, fog lights are considered accessories to vehicles and are not required. Their use, however, may be considered essential in certain driving conditions. Fog lights are installed below standard headlights and have a dimmer output, meant to create a bar of extra light on the road to assist drivers in low-visibility situations.
Florida law states that fog lights may be used in addition to low-beam headlights. However, fog lamps are not meant to replace the use of standard headlights while driving. The use of headlamps is required on all vehicles between sunset to sunrise, anytime the windshield wipers are in use (rain), or in conditions of fog, smoke, or mist.
Because fog lights are only meant to be supplementary and increase visibility of road markings, it is recommended that their use coincide with slower driving speeds. Bear in mind that it is illegal to use fog lights in Florida when there are other vehicles on the road, EXCEPT in foggy conditions.