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From: alw@mit-eddie.UUCP (Alan Wu)
Newsgroups: net.auto
Subject: Re: Third Brake Light (add one yourself for pre-86 cars).
Message-ID: <927@mit-eddie.UUCP>
Date: Sat, 11-Jan-86 01:45:04 EST
Article-I.D.: mit-eddi.927
Posted: Sat Jan 11 01:45:04 1986
Date-Received: Mon, 13-Jan-86 08:10:53 EST
References: <172@hropus.UUCP> <3217@hplabsb.UUCP> <3109@sun.uucp>
Reply-To: alw@mit-eddie.UUCP (Alan Wu)
Followup-To: net.auto
Organization: MIT, Cambridge, MA
Lines: 42
Keywords: third brake light

In article <3109@sun.uucp> chuq@sun.uucp (Chuq Von Rospach) writes:
>The Big Brother is the NHTSA, and the studies have shown a 50% reduction in
>rear-end accidents when there is a brake light visible at viewing level. It
>isn't because it looks like a police car, but simply because you see if it you
>are looking beyond the car in front of you -- the lower brake lights can get
>missed if you aren't paying attention to them.

I think there are several reasons that third brake lights work, beyond
simple novelty.
  1. They are at eye level, in the center of the following driver's field
of vision.
  2. They can be seen through the windshields of several cars in a row.
This gives drivers further back additional time to react, and reduces
the likelihood of "chain reaction" collisions.
  3. Perhaps most important, they are OFF at all times EXCEPT when the 
brakes are applied.  The transition from off to on is much easier to
perceive and interpret than a change in brightness (especially when 
the latter may be accompanied by a blinking turn signal).

Third brake lights work and are very cost-effective.  I installed one
on my new car 3 years ago, and have experienced several incidents that
would have been rear-end collisions were it not for the additional
safety margin afforded by third brake lights.

The most notable incident occurred when my wife stopped at a traffic
light last fall.  The kids behind us were going maybe 30 mph and were
not paying much attention (they were lost).  I saw some headlights
rush up behind us, heard the tires screech, and braced for a violent
impact.  The crunch that happened was almost an anticlimax, in view
of what could have happened.  When I got out, I initially had trouble
identifying where the impact had occurred.  What I discovered was that
the right headlight of their car had hit our license plate, which
is mounted completely *below the bumper*.  In other words, the driver
behind us had braked so hard (while swerving to the left) that the 
front end of his car had "dived" more than 2 feet before impact!
If he had delayed a fraction of a second more before hitting the brakes,
his car would have come to rest 1 or 2 feet *inside* the rear end of
our car.  We considered ourselves quite fortunate to come away with
a broken license plate lamp, a broken license plate frame, and a
dented license plate as the only casualties.
-- 
--Alan Wu    UUCP: alw@mit-eddie.uucp    ARPA: alw@eddie.mit.edu.arpa