I wrote this for another bike group, I thought you might find some of the information useful.

I have been a light tester for year. 25 years as a photographer with a tra ined eye to respond to changes in light and study lighting contrast. Constantly studying ever changing lighting conditions has helped me see bike lighting effectiveness in relationship to other traffic. I do not believe anything workes to make me seen by cars, I test it to prove it works all of the time, some of the time or is just Psychological protection.

I have also studied how the eye reacts to different levels of light. I have
carefully evaluated the eyes reaction time to change when eyes are blinded by bright car head lamps, to how long it takes to see much lower intensity LED blinky lights. I have studied how the spacing of lights creates the illusion of space or can hide the true shape and size of an object.

Trying to keep things short I have found the following the be most effective.

6 and 12 volt bright helmet lamps 6 volt generator, 6 and 12 volt rechargeable battery lamps mounted to the
bars or above the front wheel. Blinky's out on the ends of the bars and lower on the fork. Multiple red led strobes spread out across the rider and the rear of a bike or trailer. Reflective side walls on tires. Rear facing reflective material on bike, rider, bag, trailer, Reflective material on Left wrist for arm signals. Front facing reflective material

If you want to read the reasoning continue on, if not, stop here.

I have been trained to act like traffic.

I do not know any electric or petroleum powered traffic that uses low watt LED blinky lights as the primary source of light to be noticed by other traffic. If low watt LED's were a sufficient light source, all car manufactures would use them to cut costs. I am traffic, I need to have similarly powerfully lights to be seen effectively by other traffic on the road.

Cars do hit other cars with bright lights, having bright lights on a bike
will not stop impacts, It will increase visibility of cyclist and reduce
incidents. I wish it could end incidents between vehicles, that is a human behavior issue.

Reflective material In your lane of traffic you should see red 10 watt light ahead of you and
white 50 watt lights behind you. Reflective material works best when there is
very little light behind it. Reflective material reflects less light than it receives. As a rider you are for the most part directly in front of the motor vehicles 50 watt head lamps. Your material will reflect 30% to 70% of this light, which is much more light than the 10 watt red lamps ahead of the rider. This makes rear facing reflective material greatly effective at all times.

Front facing reflective materials are very effective when you are alone on
the road ways. You are not positioned directly ahead of oncoming car
headlamps, you are off to their side and out of the strongest part of their headlight beam. On coming traffic can easily distinguish you from the darker background. When you ride on the right side of the road you are not straight in front of oncoming head lamps where the light is focused and the brightest, you are on the far side or the edge of their lamps beam. You may only receive 10 watt of the 50 watts of light coming from their lamps and you are reflecting even less of that light. To reduce the effectiveness of reflective material even more the traffic behind you is backlighting you with 50 watt lamps this makes the few watts of light coming from the vest almost invisible.

All of this is bull unless you can test it. I have tested it and you can
too. Have a friend put all your reflective stuff on. Get a bright hand held spot
light or a car, aiming the light down the side of the road the cyclist is not on. Have the cyclist stand still at 100 yards away 50 yards away and 25 yards away. Look at how bright the reflective material is when the cyclist has a car behind and beside them, and when there is no car around them. Have the friend switch to the same side of the road you are on with their back facing you. Look at how much more light comes off the reflective material from your hand held spot light or from your car. Watch how the reflective light changes as a car in your same lane approaches the cyclist and after they pass the cyclist and the tail lights are on the other side of them. You can also evaluate how much the reflective light changes as oncoming cars in the opposite lane pass by the cyclist. I have done this test and I was surprised and horrified by the results. I thought reflective materials worked all the time and were great. Now I know they are a part of a complete package to be seen by other traffic.

I agree with Jim and others "It's always a good idea to have lots of
reflectors. You can never have too many."

I have reflectors or reflective tape on my trailers, bike, clothing, helmet, tires, if I could get reflective teeth I would. I love having a reflective strip, cuff, glove on my left arm for night time turn signals. I sometimes put a reflective ankle strap around my wrist for signaling.

Rear lights I had a few experiences that taught me about how we perceive the size of an object by the spacing of lights. Cars with one head lamp look like a motorcycle. Trucks on dark roads out in the country appear to be farther away if the tail lights are inside the rear step instead of on the outside corners of the trailer. I was in a blinding snow storm at night looking ahead for tail lights. When I saw the lights I thought I was 150 feet away from the truck. I switched lanes only to fine I was right next to the truck instead of 150 feet away. The two tail lights were between the stair instead of on the out side corners of the trailer that threw my perception of distance off.

Same thing with bike lights. A single light from a bike has to go through a
windshield of a car before it reaches the driver. If you look at a red blinky
that is far away you will find that the normal road dust and fine scratches on the windshield change the appearance of the lights. Red lamps farther away will look larger, and light closer will look smaller. This is the reverse of what it should be. Two blinky light separated give traffic more consistent way to judge the distance they are from you. I like a blinky on the cyclist back and one on the bike. Examples: One on the helmet or back pack or courier bag or collar of clothing. The other mounted on the seat post, rack, handlebar ends, high on a trailer. The idea is to have one light low and one high to give you shape. The more lights the easier it is to show your shape to other traffic and help other traffic judge distance and closing speed. Blinky and reflective material work great on the back of your bike.

Reflective tires Something I was surprised by: Reflective sidewalls on tires. My thoughts
were what help are reflective sidewalls? If the side of a bike is in front of a
car it is a little late. All I can say is that I was wrong. I found that the
sidewalls did reflect from the front and rear. As we keep balance we turn the
tire a little to the left and right all the time. This turning back and forth allows the reflective surfaces to gather and shoot back light like a blinky. The tires strobe and catch attention in a large way. I recommend Reflective
Tires whole heartily now.

Up to now I have not talked about expensive lights. Blinkys, reflectors,
reflective tires are not super expensive to do well.

I am traffic and need to act like the rest of traffic to be seen in ALL conditions.

Bright Head Lamps I am surrounded by traffic with 50 Watt head beams. I am surrounded by
people whose iris closes down when they are facing bright head lamps. This smaller hole in the eye lets less light in and makes it harder to see dimmer low
wattage lights.

In simple language if you have a car behind you or one has just passed you,
it is likely that any oncoming traffic will not be able to see a low watt blinky or flashlight because there iris takes a while to recover and become large enough to see dimmer lights. This is why it is important to have a similar
amount of light coming off your bike as is coming of the rest of traffic.

Some newer LED lights put out the same amount of light as a 30 watt
incandescent bulb. I have seen them priced at $50 to $70.

If you know your history then you know that lights this bright were triple
that amount of money three years ago. I have one light system that cost $360 and a helmet light that was $180. Modern lights are much more affordable.

I like a 30 watt light on the bike and one on the head. One to light the
ground effectively and one to look over at traffic coming in from the side. I
like to make sure I am seen, get the attention of a driver and see their face. I like a mindful driver and I make sure I am not invisible to them.When I can see their face I know they can see my light. On the road at night I am SOL the sun god, not black invisible Ninja.

I act like traffic because I am traffic.

Christopher Wallace

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