Trek report on becoming more visible (for electric velomobile)

Trek claims that a rider becomes 80% more visible when they highlight their feet and knees. (That seems almost obvious to me but I never thought of it before.)

Of course this is not possible when riding a velomobile.

I'm thinking about adding two lights to the back of my velomobile (in addition to, and separate from my running lights, turn signals, and brake lights) having them switch on and off in sequence with pedal rotations. Similar to the "chase" lights on construction and emergency vehicles. My question is should they flash briefly with each pedal rotation, or should they turn off briefly? Which do you think would be more attention-getting?

Now that I'm writing this I realize that having them turned off briefly makes more sense because when I'm coasting I would really like them to be on. Which means I will have to make the off position somewhere in the rotation that I don't normally rest.

I'm thinking that I'll used several ring-mounted hard drive magnets with one gap on each and use two reed switches located on the frame to control the lights. I have a lot of reed switches that are normally open.

What do you think?

Improved visibility has only do with knees, feet, and pedaling in that they provide points of visual complexity and change for others.

Tying lighting to pedal motion misses the underlying cause of the Trek observation and suffers from the rate dependence you point out. If you want to get peoples attention, don't hook stuff up to replicate your cadence, just use a fixed strobe rate.

Standard 12V lighting can be strobed using a LSC-100B strobe module available from SuperBrightLeds for about $5. This offers a simple robust solution.





I use these to drive DOT LED brake lights on my bikes as very bright daytime/nighttime running lights. Applying the brakes overrides the strobe and turns the brake lights steady-ON as per normal vehicle operation. No big multi-light disco light show - just a simple unconfusing motorcycle light setup.

Since your brake wiring is already in place, you can just piggyback the strobe output onto your existing brake signal with a couple of diodes - assuming you are using 12V lighting. If you are using battery voltage for your lighting, you can still use the strobe module above, but buffer the output with a Solid State Relay or something similar (e.g. Kyotto KF0602D Relay Solid State 32 Volt DC Input 2 Amp 60 Volt DC).

I'd assume a brief flash on would be more attention getting. I'd think the subjective impression would be something appearing from nowhere rather than disappearing from the complicated background. Appearing would probably be more triggering.

But that's a guess. Surely there is a study somewhere on this?

This article agrees with Teklektik's point about motion. It has also convinced me that my next visibility mods will be foot and or knee enhancements and getting some circular reflectors of some kind on my wheels - since I don't want to change out my tires for reflective versions. But I'll look into reflective tires when they are due for a change.

https://www.bicycling.com/bikes-gear/g20017365/the-science-of-being-seen-a-guide-to-safer-riding/

It has long been known that the human eye is attracted to movement: an eons old survival tactic no doubt.

The guys around here who are seen at night are the ones with the whole bike lit up. Lights in the spokes, on pedals, on the bars, on themselves. They are lit up like a Christmas tree and easy to see.

However if you are low and not easily visible due to the height of your bike, then a mast with a rotating amber emergency light will make you visible and look official.

One of the best bike headlights I have seen was a large round car headlight wired with a circuit that made it go from off to bright then off in a 2 or 3 second cycle. It wasn't flashing so much as being given a low voltage that ramped to full voltage and then back down causing it to get brighter and dimmer through the cycle. It was much like a train light that sweeps back and forth. It worked well in the daytime as well.

Amberwolf likes big headlights because drivers see big and think your vehicle must be big. He has stories about that.

I tend to ride with red jackets with reflective materiel built in by the manufacture. That goes along with flashing headlights and taillights. I have on reflective disk on one wheel that can be seen from the side if struck by a headlight, but even with all that cars around here still turn on top of me because they are not engaged with driving so much as something else like a cell phone, the argument they just had with somebody, the alcohol they have been drinking.....it could be anything.

Edit: also, (at night) I sometimes carry a flashlight in one hand, with a strap around my wrist and when I see a car that might be a problem approaching, I wiggle the light beam on them an the car. It gets there attention. If I have to brake hard I drop the light and break. The strap keeps it attached to my wrist.

The bottom line is this, the human eye is attracted to motion and things that are lit and go round and round, or flash will attract there eye. Having them think clearly is another story.

You can light up the whole bike like a colorful UFO, but unfortunately that dosen't guarantee they'll see you and react to you as a vehicle on the road. They may see you, but instead react to you as they would a roadside advertisement, because you don't look like traffic, you look like a fancy business neon sign. :/

It may still help, since at least they *will* see you, but it may not trigger the right reactions.


Instead, if you light up like normal vehicles would, with large surface area tail and headlights and turn signals/marker lights, they'll see you and respond to you like they would slow traffic. They may still be mad at you for being "in their way" but they'll see you and react to you the right way, as far as the automatic reflexes/training goes.

YOu can have a lot of lights, that make up lots of surface area, of the proper colors (red in teh back and back sides, white and amber in the front and fornt sides), and that will increase your apparent size and visibility from a further distance, giving more reaction time to those approaching.


If you don't use rim brakes, you can use relfective tape on the rim itself, interrupted with unreflective strips of the same area. They make them in a bunch of different colors for motorcycle rims, already curved for various diameters. One of them is bound to be close enough to your rim's curvature to work.

If you really want to be seen from the side at night, get the SpokePOV from Adafruit; if people don't notice your wheels lit up with animated graphics, I don't think you might not want to be on those roads.


If you want to be seen from farther away, and to help guide people to pass you at a farther distance, it helps to brightly light the entire road surface around your bike (not necessarily the bike itself), because that is what happens with car headlights--they make a pool of moving light on the road. If you do that around your bike, at least the size of the lane (size of a car), people are more likely to pass you farther.


All of these things (except the spokePOV and rim relfectivity) is stuff I"ve tested over the years in traffic, and observed the reactions of those around me as I ride under various conditions.


In daytime, when lights are less effective (but can still help make you more visible), bright colors with large surface areas will help.

Bright Dayglo Pink is the best color, especially in poor lighting conditions like sunset and dawn.

In most environments, the next best is Dayglo Orange, but if there's a lot of tan, brown, orange, or red around, then the Dayglo Yellow would be.

A mix of colors may make it *harder* to see, so picking just one and usng that on you and the entire bike will increase the visibility.

Unfortunatley, the Dayglo colors fade, some very quickly, *especially* the pink. When I used that, here in Phoenix, it lasted only weeks before fading significantly, and in less than a year was just barely still pink (even with protective clearcoat). The Yellow and Orange versions last much longer; the frame I used to use has been outside for years now and is still fairly bright, though not as bright as it was.

If you're not parked out in the sun very much, then it's not nearly so bad, but I was having to park in the sun for hours per day in many cases.


If you do use DayGlo colors on you and the bike, you can *also* light the bike itself up with UV LEDs that shine onto the bike and you, to cause the Dayglo paint and cloth to glow as well, and you'll be even brighter than in daytime because there's so much higher contrast with the surroundings.

First of all, thank you everyone for your interesting, thought-provoking, and educational comments. I might just get a random-variable-rate chasing relay to put on the two lights.

As far as colors are concerned the National Institute of Standards and Technology found that the safety green was the easiest color to see under most lighting conditions. My company requires us to wear vests of that color when working near traffic. Otherwise, most of us wear t-shirts of that color. My Rotovelo is mostly that color.

Since I have aerodynamic discs on the front wheels I cannot do much with the spokes. I can however apply reflective strips to the wheels since I use disc brakes, and I could even put adhesive reflectors on the aerodynamic wheel discs. The back wheel is mostly under the body of the Rotovelo. The two headlights are mounted near the hatch and shine on the body. Besides the normal motorcycle tail lights, there is a white lighted whip with safety green flag on the back. Unfortunately, the whip is not lighting up at this time. Oh, and I almost forgot that I put a strobe relay on the brake lights because I found that strobes really get my attention when I'm driving behind a bus. Most of the buses in my area have brake lights that strobe and then go solid red. So I spent the money, which was very little, and the time which was not so little, to install it on the Rotovelo.

Just for the record, I remembered on my commute home tonight that it is very easy to convert a normally open magnetic reed switch to a normally closed switch. All you have to do is place a fixed magnet near the reed switch. This will cause the reed switch to close and when another magnet comes nearby it will counteract the magnetic field of the fixed magnet and cause the reed to open.

Thanks again!

amberwolf said:

......Unfortunatley, the Dayglo colors fade, some very quickly, *especially* the pink. .....

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All red pigments loose there luster quickly in the sunlight. It has to do with UV radiation.

Amberwolf,
That is a very cool idea using ultraviolet LEDs to make fluorescent colors light up at night. My one worry about that is that ultraviolet light causes eye damage.

One thing I've noticed, well one of many things, is that even the dim green indicator light on my power control panel causes about one square foot on the side of the Rotovelo to Glow. I'm not sure how visible it is from a distance, but I certainly can see it well enough from my vantage point mere inches away.

Light disperses quickly from it's origin, so something easily visible you may be completely invisible to anyone a car length away, much less at further distances where you want them to start seeing you.

As long as you point the UV LEDs away from you, but toward the dayglo surfaces, then you don't have that much to worry about. If you prefer, you could wear UV-protective eyewear. I have a set of 3M safety goggles I use when running power tools that also have UV protection. Don't know the level they protect against, but you can find varying levels of such protection. If you have a windshield, you could add UV protection to that.

I wouldn't worry about the UV affecting others, since unless they are riding along with you staring at the LEDs, their exposure time will be very short as you pass them or they pass you.

amberwolf said:

Light disperses quickly from it's origin, so something easily visible you may be completely invisible to anyone a car length away, much less at further distances where you want them to start seeing you.

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The amount of light reduces as the square of the distance. But so too does the area of the object that has been illuminated. So the brightness is pretty much the same for something regardless of the distance so long as it has a mostly diffuse surface such as paint, cloth etc. It would just be a lot smaller.

An interesting example of this is the moon. If you take a picture using a standard daylight exposure, you'll get the exposure just about right and see nice surface detail the same as any similar surface lit from a similar angle on earth - despite the 200,000 mile or so distance. As a practical matter, this breaks down for objects so far away that their diameters can no longer be resolved by the optics looking at them. When they become a dimensionless point, they get dimmer the further away they are.

So the real issues with the one foot or so area lit by the LED is that the one square feet of area isn't very big and it probably isn't' very brightly lit to begin with. So in the city it probably won't be very noticeable.

In Minneapolis, I worry more about being too visible, especially at night where criminals target you. I few years back someone threw a molitov cocktail off an overpass onto the Greenway, narrowly avoiding hitting a cyclists. And during winter kids like to huck snowballs at people riding

Updates:
The lights are all working.
Drivers are generally staying far away.
A police officer shouted over her PA system that the lights could cause "seizures, you hear?". Since the light's blink-pattern is very adjustable, they are no longer in a strobe flashing pattern but a slow blink. And, now I know that the lights are visible a block away!

Yes, those were my first thoughts upon reading, shall we say glancing, at what was posted.

wturber said:

This article agrees with Teklektik's point about motion.

Click to expand...

I changed the head lights to motorcycle lights on bars attached below the rear view mirrors. And installed turn signals on the ends of the bars. Not too aerodynamic but quite visible. The only problem is that they are really bright.

A rider may run into problems on local ordinances with lights that are anything other than white on the front and red on the rear. On the sides? Who knows. Also, as pointed out, the cops are not fond of anything that is outside their usual range of cop experience, and I have enough problems in my life w/o the po-leece entering into it. Even though my bike has decent enough lighting, what keeps me alive is the mindset that every vehicle out there is out to run me over, bright lights or not. This is based on the actual experiences that they ARE out to run me over, or it sure looks that way.

If it's dark, and I travel on my bike very little after dark, I stay off the main streets if at all possible and do the neighborhood routes to get where I want to go. The thing is, every day I see people driving cars and looking at their phones. So it doesn't matter if a vehicle is lit up like the sun, if they ain't looking where they're going you're gonna get killed. One of my main survival tactics is to steer clear of areas where students are located. College students are worse than high school drivers. Those folks are beyond dangerous.

I wouldn't ride a velomobile or recumbent at night for all the money in the world. They're far below the vehicle driver's line of sight.