Interesting Pacifica feature

Your loss...

snippage

It is so refreshing to see evidence of intelligent life on this planet. Thank you.

[paraphrased from a couple of posts: Center high mount brake lights only worked temporarily because of the novelty effect, and once all cars have them, a similar effect would be found by releasing new cars without them]

Aye caramba. Not this old canard again. This myth borders on a conspiracy theory, and with folks like Ted spouting it again and again and again like a broken record, it refuses to die.

The Center High Mount Stop Light *per se* works. As with all conspicuity devices (sidemarker lights, sidemarker reflectors, etc.) , the degree to which it worked was initially higher due to the novelty effect before settling to a lower but still significant degree of benefit.

URLs for various studies and cost-benefit analyses have been posted in these forums many times, quite recently. And when you look at the number of countries in which CHMSLs have been mandated over the last 15 years, and realise that each one of those countries did its own cost-benefit analysis and study before consenting, well, it just makes you look even more ignert than you already do for spouting on about novelty effects.

DS

You need to look up the definition of these two words. Hint: they aren't synonymous.

Matt

Hint: I never said they were synonymous. Please read the rest of the thread.

Not really..............

Good idea! :-)

| | --Geoff | (f*** the strobes, I want "attack lasers" behind my grille...) | |

Maryland state police use LED lights on their vehicles, even their un-marked cruisers. and, they use a *lot* of lights on their marked vehicles.

earlier today I was on a highway, and saw their LED flashers a half-mile back in my mirrors. they shot past me at over 100mph and could see their lights for at least a mile.

when they passed, the lights were extremely bright. brighter than any standard lights I see in Delaware. tonight, I passed an unmarked car with LEDs on a shoulder (writing a ticket). they were bright, but not blindingly so.

I sure have no reason to doubt that based on what I've seen, though to be fair there are a few types of LED flashers that aren't up to par (and some standard-round LED semi taillights are too bright and too point-source as well, but I digress). The Dane County Sheriff's Department has some on its breakdown truck that are rather ineffectual--like a fixed flasher unit you'd see on the corners of an ambulance, just below the roofline, but divided into four separate red/blue sections, two each side that flash alternately to one anther. Each section is too damn small and not bright enough. by _any_ reasonable appraisal. Though this may be a limitation due to conceptual flaws rather than the LEDs used themselves. And AFAIK I don't see them being listed by anyone anymore either, they might be a year or two old and now discontinued.

--Aardwolf.

Dan, some of that was exaggeration to be funny - don't think that I seriously was suggesting that removing the CHMSL would help with rear end collisions.

Ah, you at least are admitting that. However I disagree that there is any significant degree of benefit.

Hmm this is from the person who says that the US is preventing Canada from mandating amber turn signals? Why does every country have perfect control over consenting to CHMSL's yet Canada does not have enough control to mandate amber turn signals?

You just can't do a good study on this. During the time period that the CHMSL's were put into effect, other safety improvements (such as ABS) that would have reduced rear-end collisions also became more prevalent.

Also, automotive styling has changed, it seems today that smaller tail lights are more popular, which would of course increased the importance of a CHMSL.

I also see CHMSLs all over the map, some are at eye-level, others at the top of the vehicle. Some are big, some are small. Has anyone done a study on what specific design of a CHMSL is most effective? And why not mandate that design? (because it doesen't matter if they are there or not, that's why, so let the stylists put them wherever they want)

And, let's look at the theory a second - the theory is that CHMSL's put a big red light right in the tailing drivers face so he notices a brake light faster - only problem here is that the tailing driver doesen't sit in the CENTER of the car! He sits on the left. If the theory of the CHMSL really worked, then you would see an even MORE improvement by mounting the extra stop light to the LEFT of center - except in Britian of course where it would need to go to the right of center - but once again, this isn't mandated either. Why, because once again you can't prove that there's a benefit - because the theory itself is wrong.

The problem is that this is one of these safety improvements that nobody can argue against. Costs to add an extra light to the vehicle are miniscule, there is no possible way the extra light can increase collisions, no automaker gets a competitive advantage over another because they all have to do it, and it's political suicide to argue against it because your perceived to be against "increased safety"

People claimed that the 55Mph speed limit saved thousands of lives a year, and as such this perpetuated the speed limit for nearly a generation. When it was finally repealed, all the studies claimed that it would kill thousands more people. What happened? highway deaths went _down_ after it was repealed. Of course the studies that claimed deaths would go up were quickly forgotten and swept under the rug - instead of being held up as a model of the failure of the safety study process.

For the record I am not advocating removal of the CHMSL at this point. In my opinion, the money spent on it and on justifying it was a waste, and there' s no point in spending further money proving they don't work then spending even further money getting the world's governments to again rewrite their laws. It's cheaper to just leave things as they are. But I am not under the delusion that they do any good, other than the good that is done by compensating for too-small tailight designs that should never be on the car in the first place.

Ted

On what grounds do you disagree? Personal opinion, or some data you haven't yet shared?

The very same.

The same way the US had perfect control over banning DRLs for five model years when Canada mandated them. The same way Canada has perfect control over permitting ECE headlamps while the US bans them. The same way the US has perfect control over banning fog lamps as DRLs while Canada permits them...and so on and so forth. If Canada were tomorrow to say "No more CHMSLs, we ban them", there'd be no outcry from the manufacturers, who would simply omit the device, the bulb, or leave it disconnected (as they currently do for international markets that prohibit CHMSLs, though there are fewer and fewer of those.) However, if Canada were tomorrow to say "We require amber turn signals", there would be an enormous outcry from the manufacturers on grounds of trade restriction, since they would have to tool for and equip their vehicles with a new device.

Outside North America, the situation is even clearer: When the world's lighting experts convene to discuss new ECE regulations, every country's expert has the power to kill a proposed mandatory device. All the signatory countries have to agree to a regulation's language and provisions before it's put into place. That means the specs, mandatory/optional status, wiring requirements, and just about every other aspect of any automotive lighting device usually undergo enormously protracted discussion and debate, and the mandate for the device can be held up for years if any signatory country wants to do more research or sees a reason to prohibit the device.

Perhaps *you* can't, but there exist people who can.

You've never heard of controlling for confounding factors? It's Research Methods 101 stuff.

Donno where this subjective impression gets its root in your head; I can think of plenty of vehicles with large-area taillamps...there are legal minimum projected-area requirements for all exterior lighting functions.

Yep, and you can find it and its abstract (and the whole study, if you want to pay for copying and shipping) at the UMTRI library online.

THere are legal requirements for size, position, intensity and angle of visibility of the CHMSL. Stylists are NOT allowed to put them "wherever they want".

No, the theories are:

1) The CHMSL is closer to the axis of the following driver's field of view, and 2) The CHMSL is visible through the windshield and backglass of interceding cars.

And data didn't bear this out. Data bear out the CHMSL safety benefit.

DS

Germany tried high mount brake lamps mounted at the left and at the right of the rear of the vehicle, back in the early 1980s. The safety benefit was not found to be as great as with the single center lamp.

So much for your "theory".

DS

They imported a bunch of late '70s Toronados? I would have thought they'd be a bit large for most city driving there...

--Aardwolf.

*Heh* You're not wrong - I once saw an '86 Chev Caprice Estate station wagon make a 46-point left turn from one narrow London street into another.

The German dual HMSLs were higher than the Toronado ones - about midway up the backglass.

DS

And for yours. As you said:

No, the theories are:

1) The CHMSL is closer to the axis of the following driver's field of view, and

2) The CHMSL is visible through the windshield and backglass of interceding cars.

So, when Germany put them right in the axis of the following drivers field of view, instead of off to the right (where they are when they are in the center) then the results were _worse_? So much for that theory.

"controlling for confounding factors" that's a laugh. Every study author claims to be able to do that. It's only possible when the outcome to be measured is grossly large - such as for example a study that shows something spectacular like 90% of rear-end collisions were prevented by CHMSL. Not when the outcome is barely significant.

And as for stylists not being allowed to put them where they want, what about the CHMSL on the back of the latest Yukons? It's a row of tiny LEDs that is on the very top of the vehicle - definitely way too high to be visible "through the windshield and backglass of interceding cars" and if you drive to about the 8:00 position of the Yukon and look up to your right, the rise of the back door makes them practically invisible.

And as for the retooling costs goes, if Canada mandated amber there would be an outcry, if Canada mandated the CHMSL _before_ the US did, then there would be an outcry using your logic. Yet you said that every country was free to adopt the CHMSL or not as they chose? Bullshit. It sounds like every country was only free to adopt them when the major automaking countries had decided to get together and adopt them, thus guarenteeing that just about every car made already had the light in it. Only in that kind of situation - where the light exists regardless - can a country not adopt them and just have the automakers disconnect the wire.

Your description sounds very much like the attitude I said that I have taken - once the major countries had been snowballed into doing them by the do-gooders, the rest of the world figured they wern't going to waste time on fighting such an insignificant issue. As you said "mandate for the device can be held up for years if any signatory country wants to do more research or sees a reason to prohibit the device." well why would anyone see a reason to prohibit a lighting device that does nothing?

Ted

It all depends on what the user wants. A police cruiser in the US may have absolutely no desire for a beacon (in fact, I haven't seen a beacon on a police car here in at least the past ten years), but slow-moving vehicles like forklifts, parking enforcement, security patrols, etc. require only the basics that a beacon provides. Police have higher intensity requirements, but both types are warning lamps.

The "Plastic Vantastic" Pontiac Trans Sport has the whole shebang running from roof hight down to wasteline - plus the center lamp.

Its non-standard and not (strictly) legal. Its also a hellishly BAD idea, right up there with blue-tinted bulbs and clear turn signals... and quite often found on the same idiot-mobiles that have those features too. Signal lights do standardized things for a very good reason... so that no one gets killed while trying to figure out WTF a non-standard blinking light "means".

Worst offender locally- the city bus system with their non-standard "deceleration lamps." Is he stopping? No. Is he signalling a turn? No. Is he actually slowing down? Not perceptibly. So we get a blinking christmas tree of amber lights that mean NOTHING and distract from the two small signals that really DO mean something. What are these people smoking?

Worse than with a single, center-mounted lamp. Yes.

OK, so you disagree with reams of data garnered from simulations, controlled-environment studies and quantified real-world experience, because the data don't match your opinion which is based on nothing but...your opinion.

Just so we know where you stand.

I'm not aware of any such study.

It's within the positional requirements of North American and international European regulations.

You can see that CHMSL over the roof of the Chevrolet Caprice in front of you even if you're in a Civic. What's your point?

If you're at the 8:00 position relative to the Yukon, you aren't within the angle of visibility the CHMSL is intended to cover. This objection is like saying you can't see the right front turn signal when you're standing next to the driver's door.

Quite correct. The US runs the show in North America. Regulators in Canada and, to a lesser degree, in Mexico don't like it, but that's the way it is. By and (very) large, what the US says goes.

Pardon my apparent lack of explicitness: This refers to the many countries outside North America that adhere to ECE regulations. So that's all of Europe, all of Scandinavia, most of Asia, Russia, Australia, New Zealand, South Africa and a great many more I'm not listing here.

It doesn't work this way. For seven years, CHMSLs weren't allowed in Germany or in the middle eastern countries, amongst many others. US vehicles shipped to those countries for sale as new had the CHMSL removed or the lens blacked out and the bulb removed. Remember also that the CHMSL required in North America is different from the rest-of-world one. There's a significant amount of overlap in the design, performance and mounting specs, so it's fairly easy to make a "World CHMSL", but it's not automatic. Same goes for every other exterior lighting and signalling device.

Right, because your guesses and opinions trump data...

Didn't happen like this, either. See above.

Consumer cost protection, perceived safety detriment, national stubbornness...there are all kinds of reasons.

Remember that the European approach to automotive equipment regulation is conceptually opposite to the North American approach in that in most European countries, a device or function is not allowed unless it is known to be safe, while in North America, a device or function is allowed unless it is known to be unsafe.

DS