headlights on all day

Fred W wrote:
> Ulf wrote:
>
> > I don't get how BMW can be stupid enough to use the high beams as DRLs.
> > Turn signals, fog lights or low beams at a reduced voltage would have
> > been much better...
>
> Actually, no. The high beams at reduced intensity are the best option

Aren't. It's robustly demonstrated in all the world's DRL studies that
most of the safety benefit from DRLs is in reduction of *angular*
collisions with pedestrians, cyclists and other vehicles -- not in
head-on or near-head-on collisions. It is essentially impossible to
produce a lamp that gives good high beam performance at full voltage,
AND can be run at reduced intensity such that it produces a wide enough
cone of illumination to give significant improvements in angular
conspicuity without producing far too much glare on axis. High-beam
DRLs tend to illuminate at the maximum allowable intensities on axis (=
excessive glare) but at or near the minimum allowable intensities
laterally off-axis (= insufficient angular conspicuity, therefore
minimal actual safety performance benefit). In addition, high-beam DRLs
share the disadvantages of all headlamp-based DRLs: They consume so
much power that their use is akin to opening the refrigerator door,
pulling up a chair and using the fridge light to read a book, and they
are too often improperly used instead of full-voltage headlamps after
dark, because they create the appearance of a light beam in front of
the car -- drivers and cops often can't tell the difference, or don't
care. Come up to Canada sometime and see for yourself! This use of
headlamp-based DRLs after dark creates various unsafe situations: Cars
unlit from the sides and rear, cars producing much too much glare for
other road users and too much backdazzle in bad weather, etc.

Low-beam DRLs have the energy-inefficiency problem, as well as the
conundrum that a good low-beam light distribution is opposite what is
needed for a good DRL light distribution.

And, there is the bulb life problem with all headlamp-based DRLs. The
effective decrease in lifespan pushes makers to use long-life bulbs,
which give reduced luminance and poorer beam focus, resulting in
diminished headlamp performance after dark.

The best DRLs are functionally-specific ones. The second-best ones are
the front turn signals burned full time.

Fred W wrote:

> "Angle" (sic) eyes are not DRLs.

They are on the newest 3er in Europe, and will be in North America,
too, soon.

> I suppose that they they take the
> place of "city lights" in those obscure European places that still
> require such,

As has been pointed out to you, "city lights" = parking lamps = front
position lamps, and they are mandatory on all motor vehicles under all
worldwide regulations.

> DRLs are *supposed* to be obnoxious.

Incorrect. They are supposed to be *conspicuous*. Not the same.

Fred W wrote:

> There are no requirements to have or use parking lights or city lights
> anywhere in the US that I am aware of.

Federal Motor Vehicle Safety Standard 108, Canada Motor Vehicle Safety
Standard 108, and ECE Regulation 48 all require front position lamps
("parking lamps" in North America, "city lights" colloquially mostly by
North Americans talking about European cars). Ergo, these lamps are
required all over the world.

> What is required are
> "running lights" which are usually the same lamps that you might call
> "parking lights" except they are illuminated while driving so that other
> drivers can get a sense of the width of the vehicle, especially in the
> event of a burnt out headlamp.

The lamps you describe are not called "running lights" anywhere in the
world. They are referred to as "front position lamps" in international
ECE regulations, and "parking lamps" in North American regulations.
They are required to remain illuminated with headlamps for the reason
you state (vehicle position and width indication in the event of a
burned out headlamp).

> High beams even at full voltage are not too bright to be used as DRLs
> when they are intended to be used, DURING THE DAY!!! They are run at
> reduced level to save the headlamps from burning out, not to decrease
> glare to oncoming drivers.

Incorrect. The maximum permissible axial intensity for DRLs anywhere in
the world is 7,000 candela, for North American high-beam DRLs. The
MINIMUM allowable axial intensity for high beam headlamps anywhere in
the world is 20,000 candela, for the very weakest type of headlamps
(those equipped with HB1/9004 bulbs in North America; those equipped
with R2 non-halogen bulbs in ECE countries).

> During daylight hours your pupils are
> adjusted to the higher ambient light and glare from headlights is not an
> issue.

Incorrect. Regardless of the presence, absence or degree of discomfort
due to glare, there is ALWAYS reduction in visual acuity due to glare.

> You may be irritated by these headlights, but you know they are
> there, so they are accomplishing their goal.

You are again confusing glare with conspicuity. They are not the same.
By your logic, ALL vehicle lamps would have to be painfully glaring in
order to be effective --- turn signals, brake lights, etc.

> Do you have some evidence that high beam running lights are illegal
> everywhere except North America? I kind of doubt that this is true.

Your doubt notwithstanding, ECE Regulation 87 (Daytime Running Lamps
for Motor Vehicles) and ECE Regulation 48 (Installation and Wiring of
Lighting and Signalling Devices) do not permit the use of high beams as
DRLs, at any intensity level. ECE regulations are in force virtually
everywhere in the world except North America. QED.

You may want to spend some time on Wikipedia at the articles entitled
"Headlamp", "Automotive Lighting", and "Daytime Running Lamp". You can
probably get a great many of your misunderstandings and incorrect
conclusions cleared up with just those three articles. If that's not to
your liking, then I recommend spending a couple of weeks' worth of 9-5
days at the UMTRI library in Ann Arbor, MI.

DS

Thanks Dan, it's nice to see some authoritative responses on usenet.

--
Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home pages: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

In article . com>,
Daniel J. Stern > wrote:
> The lamps you describe are not called "running lights" anywhere in the
> world. They are referred to as "front position lamps" in international
> ECE regulations, and "parking lamps" in North American regulations.

Side lights in the UK. Parking lights used to be a separate single bulb
device mounted about the middle of the car with a clear lens to the front,
red to the back. Some clipped on to the driver's door window. They were
needed in any towns without street lighting - or more usually when it was
switched off after a certain time at night. Very few if any these days,
though.

The more modern German version which allows just one front and tail
light for overnight parking etc would be legal in the UK as a parking
light, but not all UK cars are so fitted.

--
*Reality is the illusion that occurs due to the lack of alcohol *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
> In article . com>,
> Daniel J. Stern > wrote:
> > The lamps you describe are not called "running lights" anywhere in the
> > world. They are referred to as "front position lamps" in international
> > ECE regulations, and "parking lamps" in North American regulations.
>
> Side lights in the UK.

Obsolete term that has been replaced in the most current versions of
the UK regulations with "front position lamps". However, colloquial
usage of "sidelights" to refer to the front position (US "parking") and
rear position (US "tail") lamps is still common in the UK.

The UK "sidelight" terminology arose exactly as you describe, from the
earlier devices that were permanently or temporarily mounted on the
side of the car. They created a big terminology problem when
side*marker* lights came along -- almost as big as the "driving lamp"
problem.

In article >,
Dave Plowman (News) > wrote:
>red to the back. Some clipped on to the driver's door window. They were
>needed in any towns without street lighting - or more usually when it was
>switched off after a certain time at night. Very few if any these days,
>though.

Yeal like central heating the last 1/3 will get their soon.

I remember those things.

Richard,
expat.

--
Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home pages: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

Daniel J. Stern wrote:
> Fred W wrote:
>
>>Ulf wrote:
>>
>>
>>>I don't get how BMW can be stupid enough to use the high beams as DRLs.
>>>Turn signals, fog lights or low beams at a reduced voltage would have
>>>been much better...
>>
>>Actually, no. The high beams at reduced intensity are the best option
>
>
> Aren't. It's robustly demonstrated in all the world's DRL studies that
> most of the safety benefit from DRLs is in reduction of *angular*
> collisions with pedestrians, cyclists and other vehicles -- not in
> head-on or near-head-on collisions. It is essentially impossible to
> produce a lamp that gives good high beam performance at full voltage,
> AND can be run at reduced intensity such that it produces a wide enough
> cone of illumination to give significant improvements in angular
> conspicuity without producing far too much glare on axis. High-beam
> DRLs tend to illuminate at the maximum allowable intensities on axis (=
> excessive glare) but at or near the minimum allowable intensities
> laterally off-axis (= insufficient angular conspicuity, therefore
> minimal actual safety performance benefit). In addition, high-beam DRLs
> share the disadvantages of all headlamp-based DRLs: They consume so
> much power that their use is akin to opening the refrigerator door,
> pulling up a chair and using the fridge light to read a book, and they
> are too often improperly used instead of full-voltage headlamps after
> dark, because they create the appearance of a light beam in front of
> the car -- drivers and cops often can't tell the difference, or don't
> care. Come up to Canada sometime and see for yourself! This use of
> headlamp-based DRLs after dark creates various unsafe situations: Cars
> unlit from the sides and rear, cars producing much too much glare for
> other road users and too much backdazzle in bad weather, etc.
>
> Low-beam DRLs have the energy-inefficiency problem, as well as the
> conundrum that a good low-beam light distribution is opposite what is
> needed for a good DRL light distribution.
>
> And, there is the bulb life problem with all headlamp-based DRLs. The
> effective decrease in lifespan pushes makers to use long-life bulbs,
> which give reduced luminance and poorer beam focus, resulting in
> diminished headlamp performance after dark.
>
> The best DRLs are functionally-specific ones. The second-best ones are
> the front turn signals burned full time.
>

OK, I see what you are saying. But have any cars been mass produced
with functionally specific DRLs? I am not aware of any. Or any that
have used the front turn signals either for that matter. That would
seem to be a best solution (without adding much cost to the car) if that
is what is actually needed.

--
-Fred W

Richard Sexton wrote:
> Thanks Dan, it's nice to see some authoritative responses on usenet.
>
I agree. It appears I have been make all kinds of incorrect statements.
I'll just shut up now...

I only wish Dan would frequent this newsgroup more often.

--
-Fred W

dizzy wrote:
> Fred W wrote:
>
>
>>High beams
>
>
> You're wrong.
>

Gee thanks.

--
-Fred W