Motorcycle Headlight Configuration and Conspicuity

Being seen by other motor vehicles is a critical safety factor when riding a motorcycle. Most rely on a single front headlight. There seem to be great safety disadvantages to this design. What other options could enhance safety?

Most motorcycles rely on a single white headlight for both illumination and conspicuity. Now that there is a law in North America that all cars must have daytime running lights, a motorcycle’s single white headlight may be lost on other drivers.

Some motorcycles have two headlights, in close horizontal proximity to one another. From a distance these two might simply merge together and be perceived as a single light. Other two light configurations include those with increased separation. These may allow a driver to think that the motorcycle is much further away and traveling at a slower speed than actual, all very dangerous to the motorcycle rider.

Some BMWs have offset or asymmetric headlights, which are neither horizontally nor vertically aligned. While nature likes symmetry, these odd designs might actually enhance safety. Others believe that BMW does this as a marketing ploy, used to stand out against Japanese competition. The history of BMW’s wonky headlights

The “triangle of light” configuration has the single centre headlight augmented with two horizontally aligned headlights either higher or lower than the centre. One study recommends this configuration (Triangle of Light, Japan), while another disputes its effectiveness.

The use of a differentiating colour, such as yellow, is another strategy. Yellow lights are uncommon in North America, and might allow the motorcycle to stand out from the sea of white. Yellow is also easily seen by humans in the day or at night.

Another possible configuration is a light atop the helmet, which moves with the rider’s head. This is also unique and different from a car and thus might stand out. The technical issue of how to power this light is somewhat challenging, as the rider needs to be tethered to a power cord.

With the introduction of LED lights the addition of extra headlights can be done without a huge strain on the motorcycle’s electrical system. These LED lights are very energy efficient.

Perchance a motorcycle rider might want to rethink the headlight configuration in order to increase safety.

Rajputana Customs does a one-off Triumph Bonneville with asymmetric headlights. This seems to be more for minimalist style rather than safety. There is only one rear tail light.

Rajputana Customs does a one-off Triumph Bonneville with asymmetric headlights. This seems to be more for minimalist style rather than safety. There is only one rear tail light.

Another vertically stacked headlight on a motorcycle. Interesting but no reason given for the design choice.

Another vertically stacked headlight on a motorcycle. Interesting but no reason given for the design choice.

BMW_S1000RR_asymmetric-headlights

2010 BMW S1000RR asymmetric headlights. No safety reason for the design, only that it is different. It supposedly saves some weight.

Here’s an interesting 1975 headlight study that is 178 pages long! Motorcycle Head lighting Research by Samuel P Sturgis is a long read.

It was noted that several two-lamp experimental systems which were evaluated provided a significant subjective improvement over conventional systems in terms of light output. Two-lamp systems also have the benefit of providing lamp redundancy in case of a filament outage. (pg 15 of the report)

Several headlamps were used on more than one motorcycle to examine the perceived effectiveness as a function of the motorcycle application. Several two-lamp systems were used on the 350 cc motorcycle that provided a mid-beam or auxilliary low beam which augmented the conventional
low beam. Such mid-beam systems have been favorably evaluated for automotive headlighting
applications. (pp 67)

Although the issue of motorcycle conspicuity has not been addressed by this research program, some relief to the problem of maintaining a fully charged battery while operating a headlamp in daylight may be gained by the use of a low power (low to 20w) auxilliary headlamp which would provide intensity chiefly above the horizontal axis of the lamp, an area which is generally dealt with only by high beams. This auxilliary lamp, while chiefly intended to maximize daytime conspicuity while requiring limited power, could also be selectively used at night to provide improved illumination for large motorcycle roll angle cornering maneuvers. (pp 138)

While there is mention of asymmetric headlights the report references the asymmetric vs symmetric beam pattern of a single headlight.

Sport bike has dual asymmetric headlights, one large and one small, but very close together.

Sport bike has dual asymmetric headlights, one large and one small, but very close together.

Old Honda single with asymmetric BMW GS headlights.

Old Honda single with asymmetric BMW GS headlights.

Not sure of the model, but vertical asymmetrical headlights.

Not sure of the model, but vertical asymmetrical headlights.

Another custom MC, called Una,  with asymmetrical vertically stacked small headlights.

Another custom MC, called Una, with asymmetrical vertically stacked small headlights.

A better angle for the custom called Una with the asymmetrical vertically stacked small headlights.

A better angle for the custom called Una with the asymmetrical vertically stacked small headlights.

WebBikeWorld has an article on yellow headlights: Motorcycle Light Bulbs – Improving Visibility With Yellow Bulbs

StromTrooper has a thread on yellow headlights: One Yellow Headlight?. They have a whole bunch of riders using dual headlights, one white one yellow, but they are adjacent to each other. This mixes the two lights together, muting the distinction of the yellow colour.

Here is some advice from the Automobile Insurance Society, Quebec:

Advice for motorcycle auxiliary lighting, from the Automobile Insurance Society of Quebec.

Advice for motorcycle auxiliary lighting, from the Automobile Insurance Society of Quebec.

  • Before installing headlights or auxiliary lights, make sure they will not overload the motorcycle’s electrical system. It is best to have this equipment installed by an expert.
  • Auxiliary lights can also be used as fog lights or to add to the lighting provided by the headlight’s low or high beams.
  • They are available in various sizes and ranges.
  • They should be installed as far away as possible from the main headlight and front position lights.
  • They must be placed so that they make the motorcycle easier to see, but without blinding the other road users.
  • Among the three types of lights available, LED lights only consume a fraction of the energy required to power halogen or high-intensity discharge (H.I.D.) lights for equivalent lighting.
  • Auxiliary lights make the motorcycle more visible, but they do not increase the motorcyclist’s vision.

There is no mention of auxiliary headlight colours.

Here is an article about Daytime Running Lights for Motorcycles from Australia

Rumar points out that motorcycles have a significant conspicuity disadvantage due to their smaller front cross-sectional area. This also leads to speed and distance estimation errors by other drivers. Rumar notes that a single headlamp does not provide adequate distance information and he suggests that three lamps, mounted in a triangular pattern, may assist in speed and distance estimation.

This observation by Rumar, combined with the recent studies of motorcycle accidents where most motorcycles had headlights illuminated in the daytime, indicates that single low-beam headlights might not be particularly effective as motorcycle DRLs. It is therefore necessary to consider the visual ergonomics of on-road situations when accessing the functional requirements for motorcycle DRLs.

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