Since 1978, motorcycles in the U.S. have been designed to have the headlight illuminated when the engine is running. It was a voluntary change made by the motorcycle manufacturers in an effort to increase a motorcyclist's visibility. Back in 1978, there were few automobiles equipped with daytime running lights so you might have been more likely to spot a motorcycle heading in your direction if the headlight was on. Times have changed when it comes to automobile lighting and it might be time to consider a change from the standard motorcycle headlight to a modulating one.
A modulating headlight flashes or modulates in intensity, providing an increased level of visibility for riders. At this time, I don't know of any models that come with this type of headlight as a factory installed option. Modulator kits are priced from about $50 to $150 and use a microprocessor to control the intensity of the light. Depending on the manufacturer, the microprocessor causes the light to flash at a specific frequency, between 240 (plus or minus 40) cycles per minute (CPM). This frequency is chosen because it is the most noticeable to the human eye and helps it to stand out against the constant light of traditional headlights. A word of caution, if you don't fully understand your bike's electrical system, and if you don't want to mess up your warranty, have the work done by your local bike shop.
The lights are legal in all 50 states. In Florida, they're addressed in FS 316.405 which says, “During the hours of operation between sunrise and sunset, the headlights may modulate either the upper beam or the lower beam from its maximum intensity to a lower intensity, in accordance with Federal Motor Vehicle Safety Standard 571.108”. To ensure they're only used during the day, the modulator has a sensor that allows only the regular headlight to operate after dark. Kinda makes sense, doesn't it?
While there aren't any scientific studies that support headlight modulators as an effective safety device it's hard to deny they can give you additional visibility. Traditional motorcycle headlights can be difficult to see during daylight hours or in low-light situations. A modulating headlight, on the other hand, is much more noticeable, helping other drivers and riders to see you more clearly. This can help prevent accidents and make you feel more confident when riding.
Modulating headlights is a relatively new technology in the world of motorcycles, but their popularity is growing as bikers look for ways to make other motorists aware of their presence. They can help reduce the risk of distracted drivers by providing a more noticeable and dynamic light source. This means that other drivers are more likely to see you, even if they are not paying attention as they should.
Do they help? The best example I can give is a conversation I had with my wife when a bike equipped with this type of headlight was coming towards us. “That blinking light is annoying”, she said. “Perhaps, BUT you did see the motorcycle.”