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turn signals

Discussion in 'Cars and Transportation' started by Manntis, Jun 30, 2008.

  1. Manntis

    Manntis Member

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    How is that confusing? The turn indicators pulse on and off, and on one side of the car only to indicate the direction of the turn. Braking lamps come on full, no pulsing, on both sides of the car.

    Perhaps an idiot focusing on colour only, and ignoring all other visual data, would be confused... but really; if they're that easily confused should they really be driving in the first place?
     
  2. SByer

    SByer '08 #383

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    I'm sorry, but no. Blinking red for turn indicators is lame: they go invisible in a number of situations (especially near sunset). Amber is the right answer.
     
  3. Manntis

    Manntis Member

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    #3 Manntis, Jul 1, 2008
    Last edited: Jul 1, 2008
    Having driven in North America for 20 years (driving a car with amber turn indicators, incidentally) and 2 of which were living in LA, I can say I've NEVER seen a car's red indicator go invisible on me, at sunset or otherwise. The bulbs are visible in the glare of day, darkness of night, and in between at dusk. If red were that dangerous, it wouldn't be used as a brake lamp colour.

    Amber v. red are two different ways of accomplishing the same thing. Neither is superior to the other, though red has a slight cost advantage by enabling the use of a dual filament bulb in one housing as opposed to a dedicated rear turn indicator lamp.

    You're more accustomed to, and therefore more comfortable with, a certain way and that's fine. To argue that one is more confusing or disappears at sunset is complete nonsense.
     
  4. TEG

    TEG TMC Moderator

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    Once and a while someone will be pulsing their brakes and using their red turn signal at the same time and I just see a flashing red on both sides... For a moment I am not sure if they are signaling right or left, or if they have their emergency flashers on. That was more of a problem before "CHIMSEL" (3rd brake light) which makes it more apparent when brake flashing is involved.

    Sometimes you only see part of a car obscured in front of you so you don't see the other side or the 3rd brake light.
    I prefer amber turn signals because it makes it immediately obvious that someone is signaling not pulsing their brakes even if you only see one corner of the vehicle.

    Also in a sea of red tail lights at night in heavy traffic an amber turn signal stands out more from the crowd ahead.
     
  5. Manntis

    Manntis Member

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    if they're that far ahead of you that another vehicle or several vehicles prevent you from seeing 1/2 their car and their CHMSL, why does it matter to you that they're turning anyhow? They're nowhere in your envelope.

    Nor is it at all common for someone to pulse their brakes as regularly on-off-on-off as a turn signal.

    Most people can reasonably understand that, regardless of red or amber colouring, a steady on-off-on-off on one side of a car is a turn indicator and lights on both sides coming on means braking - even if someone does pulse the brakes.

    like I said, both do the same thing. I've nothing against amber turn signals, but the arguments presented to deride red indicators have been silly ones.
     
  6. SByer

    SByer '08 #383

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    Well, the good argument is that the average time it takes to tell if a light is amber and blinking is less than the time it takes to tell is a light is red and blinking, since in the red case there's no color discernment (and, even worse, when using the double filament bulb, no positional discernment).

    In the amber case, if the bulb is on, you can tell immediately. Otherwise, it's the average time until it blinks on, or 1/4 the cycle time, for an overall average of 1/8 the cycle time.

    In the red case, the best case is if you can see the third brake light and know it's functional, in which case you still have to wait for a state change to be sure, meaning it's 1/4 cycle average, on or off. Worst case, without third brake light visibility and the blinker co-positioned with the brakes along the corner of the car (and no additional side turn markers, another particular annoyance), you have to wait for two state changes to be sure (though yes, most of us won't wait that long to assume the worst).

    In any case, why the heck would you ever argue against the additional, useful piece of information (the differentiated color)?
     
  7. Manntis

    Manntis Member

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    With red/red they commonly are co-positioned - dual filament bulbs or, more recently, nested LEDs.

    Albern was arguing red/red is confusing, but even hillbillies in the US have no trouble figuring out the red/red system. All the other arguments presented have been nonsensical (invisible at sunset? can't tell when a car far ahead and blocked by other cars is turning?) I've never said amber isn't useful, but that the reasons presented against red/red are - here it comes again - silly.
     
  8. vfx

    vfx Well-Known Member

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    How do you see something going invisible?
     
  9. TEG

    TEG TMC Moderator

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    This reminds me of something. Anyone remember the old Mercury Cougar tail-lights where it would cycle through 3 different lights in sequence so it looked like it was a moving indicator?

    coug1967lrquarter.jpg

    You have roadside signs with cycling arrows telling you to drive past in the direction of the arrow.

    [​IMG]

    So when you have directional arrows it could mean one of two things - either the object with the arrows is about to move that direction (e.g.: turn signal) or you are meant to drive into the space indicated by the arrows (roadside sign). We all know what a flashing red or yellow light means on the side of a car, but temptations to make an actual animated arrow could be risky on a car parked on the side of the road. At night someone could mistake it for a sign that just means to go ahead and pass it.
     
  10. vfx

    vfx Well-Known Member

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    TEG wrote:
    "At night someone could mistake it for a sign that just means to go ahead and pass it. "

    I thought that once too.

    I saw the LED-looking turn signal arrow that was in a SUV side view mirror and thought briefly that it looked like it was blinking/ telling me go pass them on the left.

    Reminds me of some comedian jokes.

    "I approached an intersection and wanted to go the other way. I thought it might be illegal. Then I saw the sign that said, "no, U turn"!!!"
     
  11. graham

    graham Active Member

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    I would recommend accepting pretty much anything SByer says regarding color without dispute. He is more knowledgeable than most, and is one of the rare individuals on the Internet who actually knows of what he speaks.
     
  12. TEG

    TEG TMC Moderator

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    #12 TEG, Jul 6, 2008
    Last edited: Jul 6, 2008
    Yeah, I had tried to make a point about reaction time, but SByer did a much better job pointing out why amber lights help in that regard.

    By the way, I used to think that red turns signals were the mark of a cheap car until the Acura NSX first came out. At first it had red turn signals, but then I found that was on the US model, and the Japan version had amber. Also, over the years they switched the US version to have amber turn signals as well.

    Apparently some people must think of red as better (for aesthetic reasons?) or else Acura wouldn't have gone to the trouble to make special tail lights for the initial version of the NSX.

    1992:
    1419841566_0764b14df6.jpg
    2004:
    nsx__rear.jpg
    (The NSX was in production for a long time!)
     
  13. SByer

    SByer '08 #383

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    I've thought a lot about blinker lights since the first discussion about color long ago. I've decided color's not so important as having at least three states - off, blink low and blink high. I've seen really good blinkers in red (incandescent, where the wattage, bulb, and timing are set so that the brightness is a very slightly squared sine wave), but that style in yellow is even better.

    The Roadster's LED on/off is pretty bad since it's in red. Yellow would help a very small amount, but it's the completely off part of the cycle that's the major piece of damage. If the side markers blinked out of phase with the tail markers, it would help tons. It's not the worst - that's reserved for some recent Cadillacs, which blink the LED brakelights and have no side markers!

    Yes, I spend way too much time thinking about user interface enhancements.
     
  14. vfx

    vfx Well-Known Member

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    Here are some toys to consider.
     
  15. doug

    doug Administrator / Head Moderator

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    That squared sine wave is probably just due to the thermal inertia of the filament.
     
  16. SByer

    SByer '08 #383

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    Yes, but it works. LED turn indicators should be compensating in some way for their lack of it.
     
  17. TEG

    TEG TMC Moderator

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    Yeah, I keep thinking about that stuff in the back of my head as well. Not enough to wake this post up again, but every time I see the back of a Roadster I think about those red turn signals and wonder when (if) they will change them.

    I suppose while we are at it I should mention that I am a bit fixated on the red reflectors on the back too. Those should be mounted down low so that low pointed headlights still light them up.

    I sort of like what Acura did with their TSX. The newer ones have yellow turns signals at the corners looking somewhat like arrowheads, and they have the red reflector strips mounted down as low as possible.
    review-of-the-2009-acura-tsx-rear.jpg
     
  18. TEG

    TEG TMC Moderator

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    Most (if not all) LED turns signals are an array of smaller LEDs. If one wanted to avoid the flicker of a PWM circuit you could have it turn the LEDs on in groups. 10% of them on at first, then 40% then 80% then 100% then back to 10%.

    It seems like a good idea that "off" state should just be "dim", so you can still tell that the signal is on even though it is in the low state at that moment.
     
  19. doug

    doug Administrator / Head Moderator

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    Oops, sorry I meant to say more but then had to take care of something. I started to say the squared sine wave is likely do to thermal inertia, and not any special design. The control signal is almost certainly a square wave. Of course LEDs could be controlled in such a way to simulate this. But I think it would be more effective to reduce the flash period. Amber would be preferable also.

    Since amber rear turn signals are required in Europe, I'm curious if all 2010 Roadsters will have them (i.e. not just the Euro spec cars). Also while having the turn and side indicators flash out of phase is allowed in the US, apparently it's not allowed in Europe.

    Automotive lighting - Wikipedia, the free encyclopedia
     
  20. vfx

    vfx Well-Known Member

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    That would be cool!
     

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