Niles H.

Here is a study: https://people.usd.edu/~schieber/pdf/WillanThesis.pdf

There is a summary and discussion of results beginning on page 51.

The concept of (involuntary) 'attentional conspicuity' (vs 'search conspicuity') is a potentially useful one when considering on-road, or in-traffic touring safety.

After seeing the picture of Jardine's brightly colored (blaze orange) stuffsack tattooed with a truck's tire prints, one can't help thinking of it as something of a commentary on the effectiveness of the bright-color strategy.

After following and carefully watching a cyclist recently, who had bright yellow panniers and a bright yellow jacket, along with reflectors, along with a bright flashing light, one can't help reconsidering the relative effectiveness of bright flashing lights.

jabantik00

what do "bottom-up" and "top-down" mean? what's the take home message here - that flashing lights are better or worse than fluorescent colors? don't make me read all that junk

Niles H.

"Bottom-up" is used there in the sense of drawing or attracting attention involuntarily. "Top-down" is used in the sense: you can find it if you are looking for it.

Fluorescent colors (at least the fluorescent yellow-green used in the study) did do better than other colors used in the study. Although they attracted more total glances, they attracted less total eye fixation time than the flashing LEDs used in the study. The flashing LEDs seem to have a stronger, more salient attraction, impact, or 'signature' (which is what I also observed).

The main take-home message for me is that bright flashing lights (provided they are bright enough) are the bomb.

Niles H.

Just came across this Danish study (more can be seen by clicking on 'Press Release'): https://translate.google.com/translat...istory_state0=

Daytime running improves cyclist safety markedly

A large-scale experiment with [daytime] headlights on bicycles among 4000 riders in Odense shows 32% reduction in cyclist casualties. The result is so striking that Councilman....

...particularly through the summer months, when reduction is as high as 40%.

Flashing lights seem to be more noticeable than steady lights. The 'sudden onset' of the light, and its conspicuous changes, combined with the widely recognized message sent by flashing lights, point both to greater conspicuity and to a different sort of conspicuity.

Niles H.

There is another study referenced here: https://motorcyclesafetyinfo.com/moto..._products.html

Caretaker

Yeah, and you can add 'attentional conspicuity' to your text by making every word a different colour.

Niles H.

Can you make one of them a bright flashing color?

Caretaker

No, that would be so kitch.

Niles H.

The way it is isn't?

Studies show that if you wear a blonde wig, the cars give you extra room. Mapes describes this strategy here:

https://www.amazon.com/Pedaling-Revol...3&sr=1-1-fkmr0

Caretaker

A helmet that looks like a blonde wig.

Why didn't I think of that?

Niles H.

If you imagine a whole page or whole screen -- or a whole visual field -- full of text and images, in all kinds of colors, with one bright flashing light somewhere in that field, it illustrates the principle of involuntary attraction of attention that happens with bright flashing lights.

There is another study showing that the brightness of a flashing light matters much more during the daytime than at night. At night there is no need, according to this study, for very bright flashing lights. They suggest having adjustable brightness levels.

Caretaker

These 'study' guys are so clever. Who would have ever thought that the brightness of the light would be more important in daylight?

Niles H.

Well, there is a range here, all the way up to extremely bright. And some people (quite a few people) probably would have guessed that the brighter lights would also be better at night. But they aren't. The expectation of brighter is better failed in that study, for nighttime use.

drmweaver2

All well and good but real world use is modified by local laws. Here, for instance, flashing red rear lights are now outlawed, justifably I believe, because of their interference with interpreting OTHER red lights on the road (especially) at night - specifically, vehicular brake lights.

When vehicular daytime headlight use was first becoming a "big deal" about 15-20 years ago, there were a fair number of research studies funded by the US's National Safety Foundation, various car manufacturers and some insurance companies. In the end, the cost-benefit/risk-reward bean counters, um sorry - statisticians, concluded that, while there might be some measurable difference in increasing one's visibility by others, the numbers were so low as to be nearly inconsequential. And that's with car/truck headlights during the day. Siimilar studies on motorcycle headlights tended to find a flashing headlight seriously increased one's visibility by others, even during daytime, BUT was viewed by many "other vehicular operators" as distracting and therefore unsafe.

2 more cents worth of useless information to toss into the mix.

(Note: No, I don't have references to those studies. Sorry.)

Carbonfiberboy 

If you've ever been on a group ride with people using front and rear blinkies you already know this. It's quick to pick out people with the blinkies in your mirror. Colorful clothing does help, but not so much. Especially on bright days when you're riding in and out of shadow, drivers can't see you at all because their eyes are adjusted for the bright light they're in now. Blinkies are visible in those circumstances. I always run a front white blinky and a rear red blinky. Batteries are a very minor expense.

Jardine's accident, IMO, had nothing to do with visibility. I have no doubt he would have been hit had he been running a Dinotte flasher. Some truckers and pickup drivers are just pigs. They will not move over one bit for a cyclist as a matter of personal policy. I have seen people almost hit by rear view mirrors more times than I can count. They know they will be gone with no way to hold them accountable, should they hit someone. Continuous rear-looking video would be the only solution.

Niles H.

Bikes are different from other vehicles, and their riders are much more vulnerable. Also, their presence on most streets is much less common.

Flashing rear lights are outlawed for cars? for motorcycles? for bikes? for all of the above?

Is this for the state of Louisiana or for a local area?

Niles H.

I've thought about this -- what would have happened if Jardine had been wearing a bright flashing light -- while riding (virtually) the same curve where he was hit. There is no way to know for certain. What you say is one possibility, and not an unlikely one. But there are other not-unlikely possibilities as well, and for some of those possibilities (we can't know for certain which one was actually the case, and there are multiple reasonable possibilities), a bright flashing light could have caught the attention of the driver.

The driver may simply not have seen him (reports show that this is often the case -- apparently more often that not).

I share your observations on the blinkies.

mrveloman

apparently Louisiana has revised its motor vehicle code as of 1/1/11 to require red flashing or steady rear lights on bicycles: RS 32:329 D. After December 31, 2010, no person shall operate any bicycle at nighttime on a state highway, parish road, or city street, unless such bicycle is equipped with at least one lamp emitting a red flashing light or a red light on the rear as required by Subsection B of this Section.

https://www.legis.state.la.us/lss/lss.asp?doc=88271

mike in Atlanta

Carbonfiberboy 

Yeah, that's what they all say: "I didn't see him." Horsepucky. When it's three tandems riding in line, all with bright clothing and running blinkies . . . I know they saw us. It's like a pitcher trying to brush the batter back. They just don't care. Then there was the guy who tried to kill us all - went up the road, turned around and came back at high speed on the shoulder on the wrong side of the road. He missed: we all went into the ditch - some injuries, some broken equipment. It happens. It's a dangerous sport and there's nothing that will make it safe. OTOH, so is commuting in a car. There is a moral: never give a driver who almost hits you the one-finger salute. Never! Smile and wave. Steel is harder than flesh.

B. Carfree

It looks like the flasher you needed would have come from the muzzle of an RPG. I bet that driver's parents are so proud of their offspring.

Niles H.

I'm glad the issue of aggressive and incorrigible drivers has come up. They are certainly out there, and it makes sense to be aware and reminded of their existence. But I do think these drivers are only a very small percentage -- an important small percentage, and not to be ignored or forgotten, but nonetheless a small percentage.

Inattentive drivers are probably much more common. Some drivers just don't notice you; or when they finally do notice, it's too late. I've almost taken out a couple of cyclists this way myself. In one case, I was able to swerve at the last fraction of a second, when I finally noticed him. At seventy miles per hour, reaction time alone takes up a lot of distance. He was about one third of the way out into the lane, and it would have been a very serious collision or a fatality. In the other case, I didn't see the cyclist until it was too late for me to do anything about it. Fortunately, the cyclist himself took strong evasive action, and was able to avoid a head-on by inches.

No doubt some of these reports (by drivers, saying they never saw the cyclist) are simply true. And there is also no doubt that some of them are not. There is no clear way to determine the percentages here, but I suspect that a strong majority genuinely never saw the cyclist, or saw the cyclist only when it was too late. We've all experienced moments of inattention, and have missed seeing something or other (probably much more often than we realize, since this often goes undetected or unnoticed).

Heinz Stücke describes a collision he had in Germany when a driver ran right into him and apologized immediately, with real concern, saying he just didn't see him. He also describes another cyclist's very similar collision in Germany. Both descriptions are in the Friedel Grant interview with Heinz:

www.travellingtwo.com

Jardine, the in the last days of his TransAm tour (especially on Day 54) describes how he modified his assumption that cars coming from behind were seeing him. He learned this the hard way, but has enabled others to benefit from his experience by sharing details of what happened.

https://www.rayjardine.com/adventures...nsAm/index.htm

drmweaver2

I stand corrected on the law as I guess I rememebered it bass-ackwards. Sorry.

OTOH, I still dislike flashing red lights on bikes on streets ---> to me, flashing red lights = brakes being applied, car stopped on side of road (emergency flashers) or STOP!!!! A bike continuing to move with a flashing red light violates that heuristic.

BigBlueToe

I've done my own study. When I'm driving a car I notice bicyclists. I find I notice them easier when they're wearing high visitility yellow than anything else. At night I notice people with lots of reflective material and flashing red taillights. I notice people with reflectors on their pedals, because they seem to flash as people pedal.

I see people with flashing red taillights during day rides - especially centuries. I don't think it helps much at all.

Those are the results of the BigBlueToe Visibility Study.

surfrider

The study is fine and dandy, but nothing in there that's not already known. From biology, its been known for quite an long time that a mammal's brain/eye combo is attracted by motion; that's how predators notice prey. And the prey avoids detection by staying motionless. A good exception is a heard of prey - when the heard is all moving its tough to focus on one animal (ever seen a herd of zebra on the move and try to pick out just one?). Same concepts apply to a moving bicycle(s) or a blinking light(S).

Also note that at night in low ambient lighting most colors appear to be shades of gray, not true colors. Unless there's a light shining directly on it, that neon yellow won't look like anything more than a light gray color. Refletcive material will reflect some of the ambient light giving some indication of your presence.

Wearing bright colors and lights to excess during the day gets a little odd. I don't want to be rolling down the road looking like a clown who lost his circus.