Originally Posted by Rick54
Just a question, would it be better to change the signal lens to amber instead of Red - while making this change. I am about ready to pull the trigger and make this switch when I noticed the Amber/ Yellow LED for the signal. What are your thoughts?
Originally Posted by surcy
I think 2 reds for stop, turn, and tail on each side are more distinguishable and thus the reason the mfg. installs them-- not sure about regulation requirements either.
Not trying to open a can of worms....but there are other thoughts on the amber turn signals. I'm interested in what would provide me the greatest safety for my vehicle. After reading all this (below), I'm leaning towards switching to amber signal lights on the rear of the motorhome.
Amber Rear Turn Signals Are Safer Than Red, But Few Use Them - Trailer Talk - TruckingInfo.com
Amber Rear Turn Signals Are Safer Than Red, But Few Use Them
A LIGHT FLASHING YELLOW MEANS "TURN" AND ONE FLASHING RED MEANS "STOP." THE RESULT IS LESS CONFUSION FOR DRIVERS BEHIND.
March 13, 2014
Studies show that amber turn signals reduce accidents, yet most signal lamps on the rear ends of North American automobiles, trucks and trailers are red. Why? Because amber’s not legally required, and it’s simpler and cheaper to use red for all rear-facing lamps.
Tanker fleets are more likely to use amber turn signals than other operators. This trailer also has white backup lights.
“The regulation right now is such that you can use either amber or red,” said Brad Van Riper, chief technology officer at Truck-Lite. So most trailers use a pair of red lamps on each side of the rear sill rather than three lamps – two red and an amber.
The reg is Federal Motor Vehicle Safety Standard 108, which defines what auto and truck builders must use for lighting in all directions, and the performance of the lamps and lenses. It says “yellow” for amber.
Standard 108 requires the usual white headlamps, white parking or running lamps, and red tail and stop lamps.
Trucks over 80 inches wide must have red clearance lights at rear corners, yellow clearance lamps at front corners and midway along each side of long trailers, and three red identification lamps at the upper or lower center of the rear of a trailer or truck body.
In 1963, federal authoritiesmandated yellow front turn signals to make them stand out from bright-white headlights, but continued to allow red turn signals at the rear, perhaps because red tail and stop lamps are not as bright as headlamps. That’s still the case.
Most trailers have a pair of red lights on each end of the sill, like the Truck-Lite LEDs on this Wabash unit. The one closer to the middle is a tail-stop light and the one nearer the corner is a tail-turn signal. Note that the Innotec LED clearance light is also a turn signal.
The studies supporting amber rear turn signals involved autos, but findings could be applied to trucks, Van Riper and others believe. Yet the federal authorities that did a study about five years ago have not acted on it.
“In 2008, the National Highway Traffic Safety Administration, responsible for writing U.S. vehicle safety standards, released tentative findings that amber (‘yellow’) turn signals are up to 28% more effective at avoiding crashes than red ones,” wrote automotive author Daniel Stern on the website aCarPlace.com.
“Then, in 2009, they released preliminary findings that across all situations, including those in which turn signals don’t matter,vehicles with amber rear turn signals are 5.3% less likely to be hit from behind than otherwise-identical vehicles with red ones.
“That means amber turn signals were seen as being more effective at avoiding crashes than the center third brake light mandated in 1986, with a 4.3% crash avoidance,” he wrote.
Amber rear turn signals are mandated in Europe and much of Asia, but not in the U.S. Not in Canada, either; its lighting standard is also numbered 108 and uses most of the American 108.
Truck owners may use amber rear turn signals and a few do. Most of those are tanker fleets which usually are especially conscious of safety, Van Riper says.
Managers who specify amber signals on trailers usually order three 4.5-inch lights on each side of the rear sill, with a center turn signal flanked by a tail-stop lamp as the inner one and a tail-stop lamp acting also as a clearance light at the outer position.
Wabash National seldom sees any orders for amber turn signals from its customers, says its business development manager, Mark Ehrlich. Adding a third lamp on each side complicates things a bit because the sill and wiring have to be altered to accommodate it, but it’s not an expensive option, either – probably under $150.
Many trailers have a yellow combination clearance-turn signal lamp along the bottom-center on each side. Here a red light would not be permissible because that lamp faces the side. And of course, side-mounted turn signals on trucks and tractors are yellow.
Stern, the automotive writer, is perplexed that NHTSA doesn’t require amber rear turn signals.
“Amber is the right way to do it,” he insists. “Traffic moves and changes quickly. Every single day, fractions of a second make the difference between a crash and a miss.
"Clear, unambiguous vehicle signals convey their message without requiring any decoding by other drivers – it’s a red light? It’s a brake light. It’s amber? Turn signal.”
Maybe truck operators should see it that way. Stern’s article is at Preventing accidents with amber turn signals
Preventing accidents with amber turn signals
Preventing crashes with amber turn signals
By Daniel Stern
1971 Dodge Dart
What color should rear turn signals be? In North America they’re allowed to be red or amber. Almost everywhere else in the world they have to be amber.
Amber is the right way to do it; traffic moves and changes quickly. Every single day, fractions of a second make the difference between a crash and a miss. Clear, unambiguous vehicle signals convey their message without requiring any decoding by other drivers – it’s a red light? It’s a brake light. It’s amber? Turn signal.
Amber wins over red even mentioning the less dramatic niceties: in traffic, drivers looking well ahead can make earlier and better-informed decisions about lane changes; traffic congestion is reduced. But safety regulations aren’t based on common sense; they’re based on evidence, facts, and science. So what are the facts?
In 2008, NHTSA (the U.S. National Highway Traffic Safety Administration, responsible for writing U.S. vehicle safety standards) released tentative findings that amber (“yellow”) turn signals are up to 28% more effective at avoiding crashes than red ones. Then, in 2009, they released preliminary findings that across all situations, including those in which turn signals don’t matter, vehicles with amber rear turn signals are 5.3% less likely to be hit from behind than otherwise-identical vehicles with red ones.
That means amber turn signals were seen as being more effective at avoiding crashes than the center third brake light (CHMSL) mandated in 1986 (with a 4.3% crash avoidance).
1977 amber turn signalsTentative and preliminary findings are important first steps, but the slow pace and lack of action is frustrating. This isn’t unknown territory with an unproven new technology. Amber rear signals are required in Europe, Australia, New Zealand, all of Asia (including Japan, China, and Korea), South Africa, most of South America, and virtually the entire rest of the world. Outside North America, red turn signals have been banned almost everywhere for 35 to 55 years.
There has been support for amber signals in America since the 1960s; indeed, in 1963, amber front turn signals were adopted, replacing white signals, because amber is quickly discerned from the white headlights and reflections of sunlight off chrome. But automakers rejected amber rear signals as “not cost effective.”
Volkswagen’s 1977 study concluded amber rear signals are better—though this hasn’t stopped them from equipping their current American models with red ones. Fifteen years ago the University of Michigan Transportation Research Institute, one of the world’s most respected vehicle safety research outfits, determined that following drivers react significantly faster and more accurately to the stop lamps of a vehicle with amber rear signals versus red.
Cadillac BroughamAmerican regulators, alone in the world, have for decades dismissed the idea that there might be something not very smart about trying to convey two very different messages with two (or just one!) identical red lights. So automakers play “now it’s amber, now it’s red” with rear turn signal color in the American market: amber this year, red next year, back to amber at the next facelift. And not just on Intrepids, 300s, Calibers, Tauruses, and Silverados; current Audis, BMWs, Smarts, MINIs, and Mercedes have red rear signals in America. Some of this is because stylists will use any tool at their disposal to differentiate this year’s model from last year’s.
But the stylists don’t deserve all the blame. In America, the brake light and rear turn signal must each have a lit lens area of at least 50 cm2 (7¾ in2). The American regulation calls this lit lens area “EPLLA” for Effective Projected Luminous Lens Area. This minimum-size requirement doesn’t exist outside America. It’s not such a big deal on a large vehicle where there’s plenty of space for a large rear lamp, but on smaller rear lamps space is at a premium. There often isn’t room for two lamps of at least 50 cm2, so that makes a design constraint. The solution? American regs say rear turn signals can be implemented by flashing the brake light, so the automaker needs to have only one lamp of at least 50 cm2 per side. Problem solved; the red combination brake/tail/turn lamp is legal. But should it be? Is it good enough? It has the safety drawback of red instead of amber. And with a combination lamp, a driver braking and signaling at the same time shows other drivers only two-thirds of a full brake light indication. A driver getting on and off the brakes while the turn signal's on creates a confusing mess of flashing red lights, and a faulty lamp takes out two crash-avoidance light functions instead of just one.
So it’s a plus-one, minus-one situation; America gets along without the safety benefit of amber rear turn signals on all vehicles, and the rest of the world gets along without the safety benefit of minimum signal size requirements, right?
Well...no, actually, and here’s why: there’s a good pile of evidence that amber signals do a better job than red ones, but there’s no safety-related reason for the minimum lit-size requirement. There never has been.
The minimum size was adopted in the mid-1950s when a Society of Automotive Engineers lighting committee met in Arizona and held a demonstration session to evaluate cars with different rear lighting configurations. The engineers peered at the cars as they were driven away, then voted on which systems they thought looked OK. There were two reasons for specifying minimum lit area: the lens plastics available in the 1950s weren’t very colorfast or heatproof, and requiring a minimum lit area was a way to ensure, without design-restrictive explicit requirements, that the lens would be a minimum distance away from the hot bulb, to stave off fading and cracking.
Chrysler P BodyThe other reason was to do with glare and how bright a lit surface appears – called the luminance of the surface. It’s not the same as intensity, which is how much light a lamp is producing. It’s intensity, not luminance, that determines how effectively a brake or signal light conveys its message to other drivers. But luminance bears consideration, too: a given amount of light can appear more glaring when it’s coming from a relatively small surface, because the light is “denser” – the luminance is higher – on the smaller surface than on a larger one. The minimum lit area requirement acts together with the maximum intensity requirement as an indirect, implicit luminance limit to turn addresses a theoretical concern that a very bright, very small brake or turn light could be too glaring when viewed at close distances. [Editor’s note: this turned out to be a problem anyway, as the US allows brake lights to be too intense. New technology (LEDs) in the absence of an actual luminance limit resulted in that glare problem.]
The last time NHTSA looked at the issue, in 1993, they found no evidence that a 50-cm2 lamp is any more effective at preventing crashes than a smaller lamp of the same intensity. NHTSA also found no evidence of an actual glare problem with relatively small signal lights, because a smaller lamp’s higher luminance and lower intensity balanced out pretty well with a larger lamp’s lower luminance and higher intensity. So why didn’t they change it?
“We don't find any dispositive reason to keep the requirement, but we also don’t find any dispositive reason to eliminate it,” concluded NHTSA’s report. So they kept it. That was before NHTSA’s own good evidence saying amber signals work better. Maybe now there’s a reason!
Chrysler GS Turbo 2At that time, LEDs were not yet used in primary car lights; brake and signal lights all had the familiar incandescent bulbs. And the light-dispersing surface was the lens itself, which had optical patterns on its inside surface to distribute the bulb’s light collected and amplified by the reflector. This meant the whole lens area where light was traveling through was...lit! From any viewing angle and any distance, the entire lens area appeared luminous.
Then came more advanced optics that gave us crystal-clear, optics-free lenses. The optics were moved to the reflector to create a jewel-like appearance. This changed things: no longer was the whole lens lit, but instead at close distances we see very bright spots and lines of light surrounded by dark bands and spaces. The same is true with many LED lights, which show bright dots surrounded by dark spaces. LEDs with small total area can produce high intensities that would require much larger area with a bulb-and-reflector setup. With these changes, the minimum lit area requirement no longer has any relation to the luminance or intensity produced by a car light. It’s an obsolete requirement that now stands in the way of the real safety improvement we could have if all vehicles had amber rear turn signals.
Suppose tomorrow someone waves a magic wand and the EPLLA size requirement vanishes. Automakers still like the styling freedom to choose the turn-signal color, amber or red. So we can solve most of the problem by getting rid of combination brake/turn lights, right? Well...no. All we do is exchange one set of problems for another.
With separate red brake and turn signals we have identical – and dueling – red lights right next to each other. If the driver of a Golf, Jetta, Passat, Sonata, X5, Q5, Accord coupe, or any other car with red turn signals right next to the brake lights is braking and signaling at the same time, the turn signal is practically invisible until the car behind is about to drive up the tailpipe. And here again, if the driver’s getting on and off the brake while signaling, just forget about unscrambling a coherent message from the mess of flashing red lights in the fractional moment available at speed in traffic.
Chevrolet station wagon
Some of the problem goes away if the two identical red lights, the brake light and the turn signal, are widely separated from each other. It’s instructive to look at the ECE regulations, used throughout the world, except in North America. They don't allow red rear turn signals, but they do require two bright red lights in the back: the brake light and the rear fog light, an extra-bright tail light activated by the driver when it’s foggy, so following drivers can still see the car. They look similar to each other, just like the American red brake and red turn signal, so the ECE regulations say their closest lit edges have to be at least 10 cm (4 inches) apart. That way, drivers have no problem seeing and discerning both functions. But there’s no such separation requirement for brake lights and red turn signals in American regulations.
Even with the lit-size requirement, amber rear signals have never been really tricky or costly or difficult. American cars were being sent to Australia with amber rear signals back when Ward and June were scolding Beaver Cleaver for leaving his bike in the rain. Countries like Australia accommodated U.S. cars, designed for only two rear-light colors, by allowing reversing lights to be amber or white: signal for a parallel-parking job, shift to reverse, and one amber light burned steadily while the one on the signal side flashed. Meanwhile, both red brake lights lit steadily.
Chrysler Royal HearseIt was not a bad solution; in America we have amber or white front parking lights and amber or white daytime running lights, so everyone in America knows that a pair of steady amber lights means you’re looking at the approaching end of the vehicle. The reversing light is a secondary, seldom-used light function, so there’s much less consequence of piggybacking it onto the turn signals than piggybacking the brake and turn lights. Today’s amber turn signals are often bigger and brighter than tiny, dim white reversing lights.
But even without making that kind of a change, it’s hard to think of any actual car designs that lack ample space for big-enough, bright-enough, good-looking red brake and tail lights, amber turn signals, white reverse lights, and perhaps red rear fog light functions. All it takes is a sensibly written regulation in line with the science, evidence, and facts. We don’t have that right now.
Canada has long wanted to mandate amber lights, but is handcuffed to U.S. regulations by the threat of free-trade court action. There was an international effort to develop a single global lighting equipment standard based on best practices worldwide, saving money and improving safety, with optional compliance. There would have been one standard to which an automaker could build and have a vehicle acceptable throughout the world, but if an automaker still wanted to build to specific national standards, that would have remained legal (in those countries). The effort was singlehandedly killed by U.S. refusal to allow the uniform standard to require amber signals and insistence that the rest of the world would have to roll back their regulations to the 1950s and accept red rear signals. So much for “best practices!”
Shortly after releasing their tentative and preliminary 2008-09 findings, NHTSA opened a public docket requesting comment on the matter. Naturally, there are opinions on both sides [you can add your own]. But it’s interesting to see how many ordinary drivers, with no ulterior motive or axe to grind, strongly urged NHTSA to please require amber signals.
Perhaps it’s time to think about taking a deep breath and moving the American turn signal regulation boldly into line with what the rest of the world has known since before the Beatles.