Developed and negotiated by John Forester, President

Adopted 10 November, 1979

Reprinted from American Wheelmen, December, 1979
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League Secretary Bill Hoffman reports that the proposed "Policy on Nighttime Protective Equipment" was passed by the League's Board of Directors by the following vote: In favor, 10; Gross, Hoffman, Kehew, Fulton, Goertz, Neff, Wormley, Time, Forester, Russell. Opposed, 1: Russak. Abstaining, 1: Hanson. Not voting, 3: Kutschenreuter, Coleman and Christie.

The new League policy is as follows:

1) A headlamp and rear reflector should be required by law for every cyclist operating during darkness.

Car/bike collision data, engineering analysis of traffic maneuvers, and practical experience in nighttime cycling show that an adequate front headlamp and a bright rear reflector: a) protect against the large majority of car/bike collisions caused by darkness; b) enable the cyclist to fulfill his responsibility as a driver of a vehicle to alert other road users of his approach; c) illuminate the highway so the cyclist can see where he is going and avoid hazards along his path.

2) Front-facing and side-facing reflectors are not adequate substitutes for a headlamp and should not be required by law.

The evidence listed in paragraph 1 also strongly suggests that front-facing reflectors do not reduce car/bike collisions whether used alone or in conjunction with an adequate headlamp; it is obvious that these reflectors neither alert other users of the cyclist's approach nor illuminate the cyclist's path. The League disagrees with the conclusion of the Federal Consumer Product Safety Commission that front-facing and side-facing reflectors "will provide an adequate level of visibility to motorists under lowlight conditions" because in the great majority of motorist-caused car/bike collision situations the motorist's headlamp beams are not pointed toward the cyclist's side- and front-facing reflectors when the motorist initiates the action that causes the collision.

3) The headlamp must satisfactorily perform two functions: illuminating the roadway and alerting other road users to the cyclist's presence. The headlamp need operate only when the cyclist is moving.

The adequacy of the roadway illumination should be judged by the cyclist in accordance with his needs, because different travelling conditions and different cycling abilities require different performance characteristics, and no one type of equipment can be optimized for all conditions.

The alerting function must be provided over an arc of 70 degrees on each side of the bicycle's centerline. In general, any lamp which is bright enough to illuminate the roadway and whose lamp filament is visible over this arc provides sufficient light to alert other road users when they are not simultaneously alerted by motor-vehicle headlamps.

None of the accepted cyclist accident studies report any accidents in which a lawfully stationary cyclist was hit from the front during darkness. Furthermore, since any cyclist (or any driver) who intends to start from a stopped position must first yield the right of way to approaching drivers, it is not necessary for them to see him 1111111until he has restarted.

4) The rear-facing reflector should have adequate reflective power through an arc of 20 degrees on each side of the bicycle. The more powerful the reflector, the better. The preferred color for rear reflectors should be amber. Red is acceptable. White should not be acceptable.

A rear reflector is least effective on curving roads, particularly on a left curving road when the following motor vehicle driver is using low headlamp beams and sits high above his headlamps. Increasing the arc of retroreflective action, such as is done for the CPSC reflectors, is ineffective. The problem is not that the headlamp is outside the 20 degree limit of full retro-reflectivity for the reflector, but that the reflector occupies an area where the headlamp distributes comparatively little light. Therefore the appropriate countermeasure is not to increase the arc of retroreflective action but to increase the size of the reflector so that it intercepts more light from the headlamp. The largest and brightest commonly available reflector is the 3" diameter reflector sold in auto accessory stores; its performance should be the basis for any performance standards. Since amber reflectors are brighter than red reflectors of the same construction, amber should be permitted because it is brighter but not confusing to highway users. White, although brighter still, should not be permitted because it indicates an approaching vehicle. The CPSC three-panel wide-angle rear reflector now required by federal law should be replaced by the 3" diameter reflector because the CPSC reflector sacrifices reflective power over the normal arc of approach in order to gain reflective power at angles from which motor vehicles do not approach.

Because tests have shown that the roadway and objects upon it cannot be seen by motor vehicle headlamps unless a normally positioned rear reflector at that location is also plainly visible, the League presumes that, except under special circumstances, a driver who hits a properly reflectorized cyclist from the rear in darkness either has been inattentive or has been exceeding the speed limit for his headlamps and the driving conditions.

5) Cyclists should use a rear lamp in addition to the rear reflector if they plan to ride under conditions where the reflector alone may be inadequate.

Cyclists should exercise their own judgment in determining whether or not a rear reflector alone will suffice. Conditions where one may not be adequate include, among others, narrow roads with heavy traffic in both directions, excessive glare or other visual clutter to distract drivers, and narrow, curving, rural roads.

6) There should be no restrictions on the use of additional lights, flashing lights, or reflectors, provided that white is used only at the front of the bicycle and that motor-vehicle lighting limits are not exceeded.

The difficulty in providing adequate bicycle lighting has always been the difficulty of providing sufficient power for illumination. To illuminate a pair of modern motor-vehicle headlamps would require the total power of the average cyclist, while the modern bicycle generator headlamp still requires about 5 percent of the cyclist's average power. Significant efforts have been made to increase nighttime bicycle conspicuity in three ways: a) to increase the power available through the use of storage batteries charged before riding or through the use of acetylene gas generated from carbide and water as lamp fuel; b) to increase the conspicuity for a given average power consumption by using flashing lights; c) by increasing the conspicuity of reflectors by attaching them to moving parts of the bicycle. None of these efforts is so generally effective and practical that it should be required by law, but none should be prohibited for those whose circumstances make it useful.

Acetylene lamps are useful as headlamps but impractical as rear lamps, while storage batteries may power both head and rear lamps. However, the effect upon headlamps would not require any changes in laws or recommendations.

Other rearward protective devices should be evaluated against the recommended 3" diameter amber reflector. On straight roads where this is well within the motorist's headlamp beams it is a bright as a rear lamp of about the same power as the normal bicycle headlamp, so that if better performance is desired the rear lamp must be somewhat more powerful than the normal headlamp. However, on curving roads where the reflector is less well illuminated by motor-vehicle headlamps, a lower powered rear lamp may be brighter than the reflector under those circumstances.

A flashing light can be seen at much greater distances than can a steady-burning light with the same average power consumption, but it must be recognized that searching for an object and car/bike collision avoidance are diametrically opposed activities. One intends to approach an object which otherwise would be passed at a great distance, while the other intends to avoid an object which otherwise would be hit. At the short ranges typical of collision avoidance maneuvers the standard reflector or its equivalent lamp is presumably as effective as the flashing lamp.

The principal advantage claimed for both the flashing lights and for moving reflectors is that they attract the attention of the motorist before he would normally look at the cyclist. Attracting the attention of a motorist who is looking elsewhere can prevent a collision only if the motorist would otherwise not look at the cyclist until too late to avoid the collision. Not looking where one is going is unlawful and negligent, but it is not known how many nighttime motorist-overtaking car/bike collisions are so caused.

Whether moving reflectors of the pedal-mounted type would indeed attract the attention of a motorist who is looking elsewhere before the normal rear reflector would do so is exceedingly doubtful. The area of a pedal reflector is less than 15 percent of the area of the recommended rear reflector, and since it faces to the rear it should not be white. It seems unlikely that any pedalling motion would make a pedal reflector visible before the normal reflector which is seven times brighter.

While there appears to be no reason to prohibit additional or flashing lights, or moving reflectors, there is neither analytical nor accident data sufficient to demonstrate that they reduce car/bike collisions, and in addition there substantial reason to believe that pedal reflectors ar less effective than the recommended normal rear reflector.

7) The League welcomes research into how well this equipment performs its traffic safety and mobility functions, into new and improved equipment, and into protection against significant risks which are not covered by the equipment discussed in this statement.

Cycling during darkness can never be as safe as cycling in daylight, just as is true of all other highway travel. The League believes that this policy represents all reasonable legal requirements and recommended equipment, based upon present knowledge, for mitigating the additional risk of cycling during darkness. However, some of the uncertainties in our knowledge are indicated above, while others may be discovered.



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