For 20 years I've been telling people about a headlight I used in the Denver area. A 6 volt, 100 watt, PAR 36 aircraft landing light with a C6 shielded filament. Much like a police car spotlight with enough light leaking out the sides to cover the road shoulders while the main beam lights up intersections one and two blocks ahead. This was the kind of light a DUI on a cell phone would notice. I have now found a source (Bulbtronics) for a 12 volt equivalent. The GE number is 24768. Sure you need a big battery but how many of your headlights can be used to warm your hands on a cold night?