It has the safety drawback of red instead of amber. Problem solved the red combination brake/tail/turn lamp is legal. There often isn’t room for two lamps of at least 50 cm 2, so that makes a design constraint.Īmerican 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 cm 2 per side. 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.
This minimum-size requirement doesn’t exist outside America. The American regulation calls this lit lens area “EPLLA” for Effective Projected Luminous Lens Area. In America, the brake light and rear turn signal must each have a lit lens area of at least 50 cm 2 (7¾ in 2). Even imports have red rear signals in America, sometime because stylists will use any tool at their disposal to differentiate this year’s model from last year’s. 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.
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But automakers rejected amber rear signals as “not cost effective.” Volkswagen’s 1977 study concluded amber rear signals are better-but now they use red ones on their American cars.įifteen 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.Īmerican regulators, alone in the world, have dismissed the idea that there might be something wrong with trying to convey two very different messages with two (or just one!) identical red lights. There has been support for amber signals in America since the 1960s indeed, in 1963, amber front turn signals replaced white ones, because amber is quickly separated from white headlights and reflections of sunlight off chrome. Outside North America, red turn signals have been banned almost everywhere for 35 to 55 years. Amber rear signals are required in Europe, Australia, New Zealand, Asia (including Japan, China, and Korea), South Africa, and most of South America. This isn’t unknown territory, an unproven new technology, or even an expensive proposition. Those are important first steps, but the slow pace and lack of action is frustrating. 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).
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. vehicle safety standards) released tentative findings that amber (“yellow”) turn signals are up to 28% more effective at avoiding crashes than red ones. National Highway Traffic Safety Administration, responsible for writing U.S.
But safety regulations aren’t based on common sense they’re supposed to be based on evidence, facts, and science. That means that clear, unambiguous brake and turn signals must convey their message without requiring any unnecessary decoding - as in, a red light = brakes and amber = turn.Īmber wins over red even without the less dramatic niceties: in traffic, drivers looking well ahead can make better decisions about lane changes traffic congestion is reduced. Fractions of a second make the difference between a crash and a miss. Almost everywhere else in the world, they have to be amber. What color should rear turn signals be? In North America they’re usually red, and can also be amber.