Why Bike Lights?


Bill asked:

  1. In what year were lights required on bikes?
  2. Why were lights required on bikes – Is there a particular study FDOT or NHTSA or someone else determined lights were necessary?


It would seem that since bicycles are vehicles and their operators have the same rights and duties as other drivers, similar rules about lighting would apply. Numerous studies show that riding without lights at night is dangerous and results in a large proportion of crashes, injuries and deaths. Here is an article about that:


A Google search will show many more, but I don’t know which were actually used to justify the law, nor do I know the legislative history of the law.  That is beyond the scope of this site.

3 Comments on “Why Bike Lights?

  1. In each state, lights have been required on bicycles since the state legislature (with the concurrence of the governor) adopted such a requirement.

    In Florida, chapter 316 (“Florida Uniform Traffic Control Law”) was comprehensively revised in 1971 on the national model of the “Uniform Vehicle Code”, a set of recommended traffic and vehicle regulations developed and maintained by the National Committee on Uniform Traffic Laws and Ordinances. The 1968 edition of the UVC had required a bicycle used at “nighttime” to have a front lamp visible from 500 feet to the front as well as a rear reflector; a supplemental rear red light was optional. By the late 1970s, if not earlier, Florida had a bicycle lighting requirement substantially consistent with the UVC’s model requirement; on a bike’s rear, it required a working red light “after sundown”, but allowed it to be omitted if the bike had a red reflector.

    By 1985, the Florida Bicycle Council (a Governor-appointed advisory body that existed at that time) had become concerned the bicycle lighting requirement was not strong enough. In 1986 or 1987, the provision was amended to require “a bicycle in use between sunset and sunrise” to have both a rear red light and a rear reflector.

    The primary rationale for requiring front and rear lights on bicycles after sunset has been to help drivers detect cyclists. Various studies have found non-daylight conditions to be over-represented in bicycle-motor vehicle crashes.

  2. The requirement of a 500 foot lamp, both front and rear, appears to have been in the first (1926-27) pre-UVC model traffic code for almost all road-going equipment. This was true in the first UVC in 1938. By 1948 (version 5) the headlight requirement had become more sophisticated for most motor vehicles, and was now defined in candlepower for autos, trucks and motorcycles. However, horse drawn vehicles “and other equipment” still had the 500 foot requirement. By 1948 bicycles had their own rule. It was a 500 foot lamp to the front plus a reflector or 500 foot lamp to the rear. As Dwight points out, Florida changed it in 1986 to a rear reflector and a light, a rather strange variant probably based on the assumption that users would retain the ten-reflectors mandated at the point of sale by the Consumer Product Safety Commission in 1973-75, so adding the requirement for a rear lamp would amount to lamp plus reflector.

    I have been told that 500 feet was the distance that a cyclist’s acyletiline lamp of the 1880s would reach, but I have not been able to verify that. In any event, the figure is based on tradition, nothing else.

  3. In answer to the basic qestion, “in what year and why?” the answer is 1) about 1883, depending on the state, and 2) because cyclists demanded it. The League of American Wheelmen pressed the state divisions to have their respective state legislatures declare bicycles to be a carriage to avoid discriminatory bans and rules, especially in parks and along parkways. Hence, along with the designation came the requirement. There wasn’t much need for anything beyond 500 feet in the horse-drawn era. When the Hoover committee drafted the first proto-UVC in 1926, they just swept up the standard practice, which was 500 feet. By 1948 that was unworkable for motor vehicles, so the modern candlepower- based rules came in.

    The National Highway Traffic Safety Administration had a big conference on bicycle nighttime conspicuity about 1994 with a big report. It’s in the NHTSA Freedom of Information Act site. The British Traffic Safety Labratory has done a huge amount of work. So have the French. There’s a ton of information out there, because it comes up in litigation so often.

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