[Music]
if you've ever been stuck in traffic
you're familiar with the red glow of
brake lights all cars have two on the
sides and one in the center
but that wasn't always the case
older vehicles only had two what was the
reason behind this change and the
requirement of the third brake light
[Music]
to better understand the third brake
light let's talk about the history of
automotive lights
[Music]
headlights have been around since the
car was invented and their use is rather
obvious same goes for the rear lights
other motorists have to be able to see
you at night and the red lights don't
distort your vision as much as other
colors do that's why police cars use red
interior lights so when they are turned
on and off the officer's eyes will spend
less time adjusting but maybe that's for
another video but what about turn
signals our 1931 ford model a did not
originally come with turn signals
although it is outfitted with a cheap
retrofit kit from the 1980s during the
early years of car production hand
signals were used to indicate which way
you were turning this worked at the
relatively slow speeds cars would travel
as well as traffic jams hadn't really
been experienced yet as i've said in
other videos the model a was designed
with two track gravel roads in mind and
predates the invention of the highway
systems by over 20 years the turn signal
had actually been invented at this point
however in 1928 a man named edgar a
walls jr invented a system of two
flashing arrows he went to every big
auto manufacturer trying to sell his
idea
but no one wanted it some german model
a's actually came with turn signals but
they were not made by ford themselves it
wasn't until 1939 that a company called
buick fitted their vehicles with
flashway directional signals and thus
the turn signal was officially available
on a production car these signals were
only on the rear of the car in 1939 but
moved to the front and gained a
self-canceling mechanism in 1940.
throughout the next two decades turn
signals became more and more prominent
on cars however in most cases they were
still safety options and not required
they came standard on buicks and
cadillacs but were optional on gm's
other brands from anywhere between 7 and
10 us dollars which is about 140 to 200
dollars today in 2022. this went on for
several years until in 1960 washington
state made turn signals legally required
this law was quickly adapted by all u.s
states in the following years so now we
have headlights taillights and turn
signals that's good right
well maybe not
there's an issue with only having two
brake lights they are shared with the
rear running lights and often use dual
filament bulbs so the size and location
of the light was the same whether it was
used for stopping or just regular
driving with the growth of cities car
ownership and traffic jams rear-end
collisions became more and more common
the solution is problem
science of course
in 1974 psychologist dr john
veyawadsky created a small red light
that could be mounted in the rear
windows of cars he then tested his new
piece of tech by equipping it to 343
taxi cabs in san francisco he then left
the other 160 taxi cabs in the fleet
without the third brake light to use as
a control group furthermore the taxi cab
company randomly assigned drivers to
their cabs avoiding driver experience
having an effect on the test these
specially fitted taxi cabs roamed around
san francisco for 10 months and their
findings were rather eye opening
taxis with the third brake light fitted
were in
60.6
fewer collisions this ended up resulting
in
61.1 percent fewer injuries to taxi
drivers and
61.8 percent fewer repairs were needed
to be done to these taxi cabs this saved
the taxicab company hundreds of
thousands of dollars in repairs the
national highway safety administration
was impressed and intrigued by the test
and thus conducted one of their own but
on a larger scale their data was very
similar concluding that third
high-mounted brake lights do in fact
help with vehicle safety so in 1986 it
became official law that all passenger
vehicles must be outfitted with a third
brake light mounted higher than the
other two brake lights they were later
required for light trucks in 1994. so if
you see a vehicle with a factory third
brake light chances are it was built
after 1986.
a good example for that is the 1985
versus 1986 mazda rx-7 seen here as you
can see the first generation fb rx-7
does not have a third brake light
however the very next year in 1986 when
it switched to the fc we do see the
implementation of a third brake light
[Music]
light technology is always changing even
today leds are now more common in
automobile lighting making them easier
to see in inclement weather in 2011 ford
pioneered the three flash turn signal
for changing lanes making it easier and
safer for motorists but next time you
see a third brake light now you know
that it was made law in the 1980s thanks
to dr veyavatsky and his taxicab
experiment
i hope you guys enjoyed this quick
little documentary i've done two
previous ones about quartz clocks and 55
mile an hour speed limits in the 1980s
if you guys would like to see any short
documentaries about car or vehicle
changes from the 1980s please leave it
in the comment section down below but
like i said i hope you guys enjoyed this
short documentary and i'm excited to
produce the next one take care guys
[Music]
you