The Washington times., 1925-06-01
AUTOISTS SPLIT
ON DAZZLING
LIGHTS
Some Favor 81 candIe-
Power. but Others See
Danger in Then,
By DONALD McDOUGAL.

BY DUINfAAIO NACASVGNAAAAs8 AAs
Some little irritation appears to-
have developed in the headlight con-
troversy in Washington, and that
lis regretiable.
The regulations can be enforced
only when there is a great morale,
q feeling of friendliness and coop
Grafton all around.
The headlight regulation as It
stands is satisfactory to numDer
motorists, including the director,
while the majority OF drivers con-
slider certain features Of it a hard
ship.
This opinion seems to be WE'LL
founded. A 21 candle-power light
with reflector behind it, makes
too dazzling a beam for any eye 10
withstand,
This fact is well recognized in
the neighboring State of Virginia.
where the law forbids the use Of
light OF more than 4 candle power,
with reflectors.
The District code makes COM
pulsory the use Of light five
times as strong.
The Virginia State law requires
tho same 200-foot range of illumina.
ton that the Washington code calls
for, with similar provisions about
dimming at hill crests, level beam,
Jete.T .ssroA Ser s5g .v9EQT
But this applies only outside OF
cities, on rural highways NFl1ere there
are no other means of lighting. and
always with the provision that no
light stronger than four.candle-
power shall be used with reflectors.
Different in Cities.
In the cities this law is super
seded by municipal regulations,
which still further relieve the
drivers eyes:
range of illumination is los feet in
stead of 200. and the lamps shall
throw bright light NOT MORE
than los feet on level ground"
ton the. light must be thrown NOT
help yourself2-and with a candle
power five times as strong as that
permitted by the State of Virginia
even in the woods.
On what Is this 200-foot range of
illumination for city driving based?
Are there any facts, any conditions,
to Justify it? A study of the regu-
lations shows that 100 feet. or per-
ilaps a. trifle more, is ample for
safety.
Every necessary foot that the
light-range is. increased, means All
unnecessary jab in the eye to other
users of tho highway. 1t means
more than that. 1t means from q
jab and a half to two jabs.
Increase In Decrease.
If it takes 20 candlepower light
to produce certain illumination
at 200 feet, it will require consider
ably less than 10 candlepoWer to
produce an equal Illumination at
100 feet
That is, when you decrease the
range, you decrease. the candle
power still more. Or. the other way
around. If the range now required
by the regulations is double the
necessary range, then our lamps are
a great deal more than 100 per cent
too bright. -
Anyhow, the District regulations
prescribe lamps five times DIS strong
as those permitted in the country
roads of Virginia. And Virginia
drivers seem TO get along without
much trouble.
Judging from IItlSJ II SSS!tlS THAI
Washington motorists complaints
are well founded.
But other prov sions of the code
show that both the range and, in
consequence, the candlepower, are
greater than is necessary.
A driver needs to see far enough
ahead to come 10 a stop. or dodge,
when any foreign eject gets in the
way.
The speed limit in the city is
twenty-five miles an hour, which
is thirty:three feet per second, ac-
cording to the approximate rule
that a vehicle runs one and a half
times as many feet per second as
is does miles per hour.
FavOrs Reduction.
If it takes a driver a second
to realize that there's something
in his path and he'd better put on
his brakes, he'll run thirty-three
feet while he's doing that: then
he'll come to a stop fifty feet
further on, or eighty.three feet al
together. 49,. ~
Allowing % per cent leeway. or
twenty-on feet, we get total of
104 feet, which is practically what
the Alexandria law shows by near
ly a years experience, to be prac-
tically correct.
A reduction in the required
range means greater proportional
reduction in the candle-power,
which in turn means shorter
dazzling beam, 80 that fewer mo-
I