"Steve" > wrote in message
...
> Daniel J. Stern wrote:
>> On Wed, 13 Oct 2004, Steve wrote:
>>
>>
>>>>Pick your badness! Do you want the "brake, tail and turn signal
>>>>functions
>>>>all lumped into one lamp, which can give only one signal at a time, and
>>>>if
>>>>it fails, you lose all functions on that side" badness?
>>>
>>>My '69 has 3 lamps per side, actually. Built-in redundancy. Problem
>>>solved.
>>
>>
>> Halfassedly.
>>
>> "If it fails, you lose all functions on that side" problem solved.
>>
>> "Can give only one signal at a time" problem UNsolved. If all a
>> surrounding driver can see is one side or the other, and you are stepping
>> on the brakes AND signalling for a turn or lanechange in the direction of
>> the only rear lamp he can see, all he sees is your blinker, NOT your
>> brake
>> light.Half the problem solved.
>
> And so how should one respond differently to a blinker or a brake? Either
> one means "this car is slowing down" so its pretty much a moot point,
> especially since both rear lamps (and the CHMSL) are going to be
> simultaneously visible 99% of the time.
>
> OTOH, seeing amber in limited visibility conditions implies "approaching
> vehicle" which is flat-out false in the case of amber rear turn signals.
> Meaning you have to rely on simultaneously seeing headlamps or taillamps
> to resolve THAT ambiguity. You're just trading one ambiguity for another,
> and I'd argue that the "signal or brake" ambiguity isn't particularly
> dangerous since you should assume that the car is slowing to a near-stop
> (at least) under either condition. The fact of the matter is that BOTH
> systems work perfectly well, both have done so for over 50 years, and I
> think you'd be hard-pressed to find a statistically different number of
> collisions based on the color of the rear turn signals, except for the
> "duelling reds" design you mentioned before. (That's your open invitation
> to prove me wrong.) :-)

International agreements, (yes the USA signed and ratified it) mandates that
amber just be used for flashing lights, front and rear and side. If the USA
followed that treaty requirement there would be no issue of having to guess
if a yellow light in the fog was the front or rear of a vehicle, it would
unambiguously tell you that a vehicle is either flashing a turn or if both
are flashing, that the vehicle is either very slow or parked. Instead, the
USA lets the car makers do whatever they want.

Has anyone done a study to show that our assumptions about amber being safer
is valid?

Richard.