Originally Posted by bicycledriving.org

Night Visibility From the Rear

Only five states require a rear lamp emitting a red light: Alaska, Florida, New Jersey, New York, and Ohio. Of these five, Alaska, Florida, and Ohio also require a rear reflector. All the remaining states require a rear reflector, and specify that a rear lamp may be used in addition to, or in some states, instead of, the rear reflector. All specify that the reflector must be red, except South Dakota, which says, “red or yellow.” All but two states specify a minimum visibility distance for rear reflectors ranging from 600 to 200 feet (see Table 1). In many states the visibility requirement is less for reflectors (300 feet) than for the optional rear light (500 feet). Three states also specify a minimum reflector size (see also Table 1). Washington says that light emitting diodes (LEDs) may be used instead of the optional rear lamp. Wisconsin says that the optional rear light may be “red or flashing amber.”