Bicycle Helmet Visibility and Conspicuity
Summary: Visibility is an important factor in reducing bicycle crashes. Helmets are a part of that.
Visibility is a big factor in bicycle traffic safety. Making your helmet conspicuous can improve your safety. If a driver sees you they will try to avoid hitting you. If they don’t hit you, you will not need to try out your helmet’s impact protection!
Limitations
Visibility is not just a matter of providing a bright color or a hot reflective spot. Drivers are seeing you against a daytime background of other moving objects, signs, and a thousand things vying for their attention. At night in the city a small light source can become part of the urban light clutter, a mosaic of light sources that can mask what and where you are on the road. Beyond that, research with motorcycles shows that the best way for a motorcycle to be highly visible on the road is to be a cop. No orange vest or daytime headlight is needed for almost every driver to see and register the motorcycle’s presence if it is a police motorcycle. So the dynamic that concerns us is related to driver eye scanning, identification and thinking as much as just putting out a bright spot. It is not the eye of the driver you are after, it’s the brain.
Blinking red LED lights have become the signature of the urban cyclist in the US. They say “bicycle ahead” better than any other type of lighting, and for that reason they may reach the driver’s consciousness better than any other small light source.
Colors
Many of today’s helmets are dull and dark, and just do not show up on the driver’s radar. In the early 1990’s there were neon helmets, but they went out of fashion. Now finally in the mid-2000’s there are more bright helmets becoming available, but sometimes the best you can do is a white helmet, which is actually the optimum color after dark, and not bad at all in daylight. Engineers have shown that white clothing after dark does not show up for long distances, but at short range you can be seen better in white than in dark colors.
A study of motorcycle conspicuity in New Zealand showed that bright helmet colors reduce the likelihood of a motorcycle rider being hit. You can read that study in the British Medical Journal. Some experts believe that a solid color works better than a splotchy design.
Reflectivity
Few manufacturers put reflective tape on helmets now, so you have to add your own. Beware of the silver tape you see on many helmets. It mimics reflective tape, but in some cases it is not, saving the manufacturer about ten cents. You can test it with a flashlight held close to your eye to be sure.
In night-time tests we helped to organize for the Consumer Product Safety Commission in the 1990’s we tried to demonstrate the effectiveness of various types and amounts of reflective tape on a helmet. If you have state-of-the-art tape, as little as a band around the helmet about three-eighths of an inch wide seemed effective to observers. Most tape on the market is still not state-of-the-art, however, and needs a wider band. Unfortunately, the CPSC scientific tests seemed to show that reflective material on helmets did not aid drivers in identifying cyclists earlier. We are still puzzled by that, but it may relate to the fact that there are not many cyclists on the road here at night and drivers are not conditioned to recognize reflective helmet patches. In addition, the helmet is far above the road surface, and car headlights are designed to concentrate their low beams on the pavement.
We hope that CPSC will some day add a reflective tape requirement to their standard. Meantime, you usually have to do it yourself. The tricky part for a consumer is making sure that the adhesive on the tape is compatible with the shell of your helmet. If not, the solvents in the adhesive could possibly attack the plastic of the shell. We have more on that subject on our page on stickers.
The New Zealand study mentioned above also tried reflective clothing on motorcycle riders and found it effective in increasing conspicuity.
Active Lights
Active lights on helmets are far superior to reflective materials. They can be seen when there are no headlights shining on you. Most of them are cheap, the batteries are often rechargeable and they last a long time. But anything you add to the outer surface of a helmet can pose a snagging hazard in a fall. There are some lights on the market with good breakaway mounts to avoid that problem, and eventually we may see thin film technology or LED’s used to bring surface lighting to helmets. In the meantime, hook-and-loop mounts are usually a good way to make sure lights are not too rigid. Adding a red blinker to the back of your helmet is a good way to supplement the lights you have mounted on your bicycle, and will improve your visibility under more conditions than using reflective tape. We use both because the tape can be seen from the sides in a full 360 degree circle, even though it requires a headlight shining on you–meaning a car headed straight for you!–to work.
There are a number of helmets on the market now with built-in lights, including some with turn signals, brake lights and other features. You can find comments on them in our most recent writeup on helmets for this season. There are many headlights that can also be added to helmets. They work well on forest trails, but less well on streets and urban bikeways, where they can blind other cyclists unless you are very careful where you look. They must always be mounted with breakaway mounts to prevent snagging them on a tree limb or in a fall and jerking your neck.
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