By John Allen

Be safe AND follow the law

As days become shorter and daylight-saving time ends, it is important for cyclists to remain visible to motorists, other cyclists, and pedestrians. When riding in the dark or near-dark, cyclists need to run lights for safety, and to comply with Massachusetts law.

The Commonwealth of Massachusetts stipulates that all cyclists must use a white headlight and red taillight if they are riding anytime from a half-hour after sunset until a half-hour before sunrise (MassBike).

Massachusetts requires the following equipment/visibility specifications for night riding (as paraphrased by MassBike):

• At night, the bike’s headlight must emit a white light visible from a distance of at least 500 feet. A generator-powered lamp that shines only when the bike is moving is okay.
• At night, your bike’s taillight must be red and must be visible from a distance of at least 600 feet.
• At night, your bike’s reflectors must be visible in the low beams of a car’s headlights from a distance of at least 600 feet. Reflectors and reflective material on your bike must be visible from the back and sides.

Cycling-specific lights have come a long way

In my early days as a cyclist, I had a few battery-powered lamps – but these would run down in a couple of hours. Rechargeable batteries appeared around 1980. These lights were bright enough for a taillight or a front-facing marker light when riding under streetlights, but were woefully inadequate for a headlight that would light the way on an unlit road. Tire-friction generators of the time produced somewhat more power, typically 3 watts (W) (typical automotive incandescent headlamp draws over 30 W).

The author riding his first Raleigh Twenty utility bicycle with his first lights that had rechargeable batteries, 1980 -- Photo credit: Sheldon Brown.

During the reign of the incandescent bulb, there were several initiatives to produce brighter bicycle lights, but the result was heavy, expensive, and/or finicky. A more detailed look into those issues may be found in an article on sheldonbrown.com.

Early efforts to encourage cyclists to use lights

Getting everyday utility bicyclists to use bicycle lights was an unwinnable battle for nearly a century. Street lighting and light pollution in urban areas could provide enough light so bicyclists could find their way, but not nearly enough to alert others to the presence of a cyclist, and especially not in the face of low-level glare from motor-vehicle headlamps and commercial lighting.  Use of lights was greater in countries where utility bicycling was popular, but a study in the United Kingdom, for example, showed that it was still only around 70%. In the US, it was far lower.

U.S. Consumer Product Safety Commission regulations required a front-facing retroreflector on new bicycles starting in the mid-1970s.  These regulations did little more than produce a false sense of security, reducing the incentive to use a headlight. Yet on the other hand, the law of every state required bicyclists to use a headlight (except for a few years, Massachusetts, but that’s another story). The law was not enforced. Crashes occurred that could have been avoided even with the weak headlights that were usual then.  But the burden of fault following a crash would be shifted to a bicyclist without proper lighting.

LEDs become the new standard

The situation began to change significantly with the advent of the red light-emitting diode in the 1990s. Why red? The energy level transition to produce red light is smaller than for other visible colors, and so red LEDs were available earlier. Now a red taillight was cheap and practical. It would attach to the same standard bracket that held a rear reflector, and would run for weeks on a pair of AA batteries.  It ran longer if it blinked. And so blinking taillights became very common.

Unintended consequence: many bicyclists rode with a taillight, and no headlight. Fine when a motorist is overtaking, no better for anyone in front of the bicyclist.

White LEDs eventually followed. Now a small and affordable bicycle headlamp can be just as bright as an automotive headlamp. It can be powered by internal batteries, or by a generator.

Generators in the front hub of bicycles are best – efficient, reliable, and quiet. They add so little drag that it is of no concern to anyone but a racer.  Newer ones weigh less and put out more power thanks to advances in magnetic materials. Generator-powered lights can also store energy to keep them shining for a few minutes while the bicyclist is stopped at a traffic light.

A headlight for use at night should have a flat-topped beam pattern like an automotive headlamp. In the USA, there is an entirely other class of bicycle headlights sold for mountain bikers or as daytime running lights. These generally have a round beam pattern rather than a flat-topped one. I don’t recommend these for nighttime use, for the same reason you wouldn’t want to use the high-beam headlights of a car with oncoming traffic.  More about choosing bicycle headlights is here: https://www.sheldonbrown.com/LED-headlights.html.

Reflectors are the law, too

Recently updated Massachusetts law states:

“During the period from one-half hour after sunset to one-half hour before sunrise, the operator shall display on each pedal of his bicycle a reflector, or around each of his ankles reflective material visible from the front and rear for a distance of six hundred feet, and reflectors or reflective material, either on said bicycle or on the person of the operator, visible on each side for a distance of six hundred feet, when directly in front of lawful lower beams of headlamps of a motor vehicle.”

A rear reflector works by shining light back in the direction it came from, and works quite well for the drivers of overtaking motor vehicles. A taillight can go out without your knowledge. Many small LED taillights these days do not include a retroreflector, so you will need a separate one. I prefer a large, amber, automotive one rather than the small red ones that come on new bicycles.

The author riding another Raleigh Twenty in 2024 with an Ixon Core IQ2 USB rechargeable headlight. On the rear is a Chinese Vistalite"blinkie"  clone, which runs for weeks of nighttime utility trips on a pair of AA batteries and includes a retroreflector.

Don’t skimp on safety

This equipment comes at a price. And with lack of law enforcement, and nonchalance, many bicyclists still ride without lights. Notably, though, many e-bikes come with lights in the standard build.

Of course, equipment is only part of the story of how to be safe, but it is an important part, so don’t skimp!