They are typically used rather than dipped-beam headlamps, reducing the glare-back from fog or falling snow, though the legality varies by jurisdiction of utilizing front fog lamps with out low beam headlamps. Forward illumination is provided by excessive- (“primary”, “full”, “driving”) and low- (“dip”, “dipped”, “passing”) beam headlamps, which may be augmented by auxiliary fog lamps, driving lamps, or cornering lamps.
The prescribed colors differ by jurisdiction; in most international locations, blue and red special warning lamps are used on police, fireplace, and medical-emergency autos. In the US it’s a violation of the DOT Uniform Vehicle Code for any non-emergency vehicle (Police/Fire/Ambulance) to operate ahead-going through red lights of any type. Some US states allow emergency autos to have blue lights that may be turned on to warn drivers of an emergency vehicle in motion; blue and purple lights can be mixed, forward- and/or rear-dealing with, additionally. In the UK, … Read More