Saturday, February 4

Back End Andy Thanks

Rear Light/Reflector Configuration I Prefer. I'm HOPING that the Combo of the Steady Light/Reflector and the Reflector Helps
My Motorists Judge When to CHANGE LANES in Order to Pass. So Far, I've Not Been Disappointed, but Nobody's Collected Statistics
Sometimes, when the commute has been even less eventful than normal, ideas come from other places on the Internet. In this case, today's post comes from a statement of Andy Cline of the "must read" Carbon Trace blog. Mostly, politics aside, Andy is pretty sensible about bikes, but his post here suggested a little info on "the back end" might be in order.

Legal, But I Like MORE
Most states, as in the case of Texas, have a lighting statute along the lines of:
Sec. 551.104. SAFETY EQUIPMENT.  ...
(b) A person may not operate a bicycle at nighttime unless the bicycle is equipped with:
(1) a lamp on the front of the bicycle that emits a white light visible from a distance of at least 500 feet in front of the bicycle; and
(2)  on  the rear of the bicycle:
(A) a red reflector that is:
(i) of a type approved by the department; and
(ii) visible when directly in front of lawful upper beams of motor vehicle headlamps from all distances from 50 to 300 feet to the rear of the bicycle; or
(B) a lamp that emits a red light visible from a distance of 500 feet to the rear of the bicycle.

If you are new to the world of cycling, you may not know that few bicycles sold new meet these legal requirements. Ironically, the FEDERAL GOVERNMENT HAS REQUIREMENTS THAT GO BEYOND THESE, BUT AT THE SAME TIME FAIL. But that is another post. The real question is what, in the way of lighting and reflectors and reflective stuff is needed on the back end? Well, I'm sorry, but I cannot tell you that. However, you may find some of the following useful in formulating that answer for yourself.

No Rear Rack? No Problem!
CPSC Reflector/Light
and Blinky Light
Reflectors and lights have very different properties. Reflectors require no batteries or electricity, but depend on light to work. Lights work as long as they have electricity. This is the root of why headlights are required but only reflectors in the rear. After all, if everyone had only reflectors in front, nobody would see oncoming traffic, but with lights in front, everyone's rear reflectors would still work.

In fact, in John Forester's book, with the most recent edition published before "blinky" rear lights became common (hint, hint), suggested that rear lights were unnecessary and that cyclists should stick to rear reflectors. What's more, he recommends AMBER reflectors because they reflect more light than the statutory RED ones. Well, maybe. But his advice isn't strictly legal in most states. GO HERE FOR MORE FROM JOHN FORESTER ON THIS.

I do more. Reading what little research on the matter exists, I concluded that the strategy I would follow consists of the following:
  • A rear reflector that conforms to the SAE standard
  • A steady rear light
  • A blinking rear light
First, the reflector. You cannot buy an SAE reflector at a bike shop. Instead, if anything, they sell an inferior CPSC reflector. Why do I claim this? Well, it is pretty simple. The CPSC reflects from directions cars are unlikely to come at a bike, like the rear quarter, in addition to some reflectance from behind. The SAE reflector works FAR better to reflect back to real world overtaking traffic. Why any reflector at all? Well, electricity can fail and you won't know it - unlike if a headlight goes out.

Second, the steady light. AND, the blinking light. The very same CPSC that fosters an inferior rear reflector did some tests. They found that a steady light is easier for an overtaking motorist to judge distance than a blinking light. On the other hand, a blinking light is identified further away. Interestingly, they did NOT show big AMBER reflectors to work any better than RED ones. That, despite double the reflecting power. I've actually purchased amber reflectors, but the data cause me to lack some motivation to "amberize" my reflector gear.

And so you have it. I carry a reflector, a steady rear light, and a blinking rear light. If a light goes out, I will typically put the remaining one into blink mode. Just to get carried away, one of the lights on my main commute bike also meets the CPSC standard.

Remember, if you think I'm getting carried away, that most of my nighttime clothing seems to trend towards "basic black." I'd rather go with the available ACTUAL RESEARCH, which is pretty minimal. And I have verified many times that overtaking motorists DO see me early. That is true even when I'm wearing my black cycling jacket, with my black cycling gloves, and I'm signaling a lane change. With no "high vis" other than what might be around my ankles to keep my pants from fouling the chain, I'm led to believe that my lights attract the motoring eye and then they readily see whatever else is happening. Would you conclude otherwise?

Lights and reflectors are cheap and work whatever you might be wearing. Ponder that...

Lights and Reflectors Without Flash. Note:
Top Reflector is Modern SAE Standard
Middle Light/Reflector is CPSC Standard
Bottom Reflector is SAE Standard from 40 Years Ago
Fuzzy Focus Doesn't Affect Reflection!
No Rear Electric Lights were Lit, so WHAT YOU SEE is What Would Show in Headlights


John said...

One advantage of lights that you didn't mention in their relative performance in fog. I learned about this from John Schubert. Fog degrades light drastically, of course, and the light reaching an overtaking motorist from a reflector will be degraded twice as much as that from a cyclist's taillight. That's because the light from the reflector is actually the car's headlights being reflected back at it, so it's making a complete round trip, whereas the cyclist's taillight is only going one way, half the distance, half the degradation. Cool fun fact.

Steve A said...

Yet one more reason I take a modified (and a mile longer) route when we get socked in by fog. When things are thick, it'll take me a FULL FIVE MINUTES LONGER to get to work. The things we sacrifice for safety!

cafiend said...

My dynamo-powered tail light includes an approved reflector. So do my right and left flashing tail lights. The Plant Bike Superflash occupies the center of my light bar/ bum bag. I wear the lights so they will be higher in the field of view for overtaking motorists.

Reflector legbands take the place of pedal reflectors. They provide 270 degrees of reflectivity on each side, increasing side visibility as well as front and rear.

As for fog, everyone should slow down but a lot of idiots don't. I have no alternate routes for most of my commute. Fog is very stressful.

Big Oak said...

Yea, fog is scary. I use two different battery-powered tallights. One blinky, one steady. But I think I'm going to add a reflector now.

I've been riding with reflective ankle bands, and added a reflective vest this winter.

John Romeo Alpha said...

++ on SAE reflectors (auto parts store BTW) and ankle bands. A ride-along with a motor vehicle driver during the hour after sunset is an excellent exercise, too. I asked if she saw the cyclists ahead, which I was watching for and could usually see at about 500 feet, and even the ones with dim blinkies she did not see. The most noticeable cyclists were the ones with ankle bands, and bright, PBSF or Radbot type 1W rear lights. The dimmer flashies get lost in the street lights and headlights of other traffic. I also continue to experiment with blinkies on helmet (must be crash-removable) as well as reflective tape (goes everywhere, frankly).

cycler said...

I don't know why more red lights don't ALSO function as a reflector, seems to make sense as a fail-safe.

Less important than with front lights, but it can be quite hard to judge the speed of something with a flashing light. So I agree that a combination of steady and blinkie lights is important.
I'm with JRA that my sweet spot is a super bright annoy-o-tron blinkie like the superflash, plus a steady red generator light.

Interestingly I've never seen a generator powered flashing light. I've read that flashing lights are illegal in the German market, and since most of the manufacturers of generator lights are either German, or have a big German market, they don't make them.

Invisible Hand said...

Some blinkies/lights are also reflectors. But simply based on anecdotes, I find that most cyclists focus on the brightness of the light and almost completely ignore the size of the light. A big blinkie/reflector really helps visibility from some experimentation with friends.

In particular for cyclists in traffic, a blinkie on the helmet helps since it is rarely obscured by cars, people, and so on.

acline said...

I'm updating my post with this link :-)

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