Post by bra Post by Heron
Our study concluded that the ART (Auditory Reaction
Time) is faster than the VRT (Visual Reaction Time)
in medical students.
The NHRA and several drag-racing training schools have always known
that if a driver reacts to the green light coming on, her total
reaction time will be 1.03 seconds --- uncompetitive.
The green light comes on at .500 seconds after the third amber lights.
NHRA reaction timers come on at the same time as the third amber,
thus 0.5 secs before the green GO.
A good driver's reaction to receiving a green light stimulus is about 0.21 secs.
A well set-up car can be moving off in 0.32 secs after that driver reaction.
Green Light: already .500 secs have passed
Driver RT: .210 secs
+ Vehicle RT: .320 secs
Yet good drivers, and I have seen them do this at local amateur
races, record "impossible" reaction times of 0.5 secs.
This means that their car broke the beam at the same instant that the
green light came on --- despite that seemingly 'inevitable' delay of
0.53 secs driver + vehicle reaction time.
They have schooled themselves to be on the gas well before the green
--- if they are very brave, at the same instant the third amber
lights --- playing with 3/100 second to avoid disqualification.
Nerves of steel.
BTW, professional drag racers experienced an adjustment when in 2003
the NHRA installed LED lights for physical reliability (top fuel
engine noise was destroying even industrial-strength filaments).
There appears to be a small but significant difference in
humanly-visible "light-up" times between incandescent bulbs and
LED's. But drivers soon learned. and average RT's actually dropped.
Yep. Well-known fact (at least in the electronics field). That's why I've
been running LED brake lights in my car ever since it was (reasonably)
possible to get them*. Most drivers seem to be multi-tasking most of the
time so having stop lamps that go from nothing to bright almost instantly
gives me a much better chance of avoiding an accident than having lamps
based on technology over a century old. Incandescant lamps are nowhere near
as eye-catching due to their innate light-up mode that is more of a slow
fade-in than an off/on cycle.
*I've been using an Hella Matrix 12x LED high-stop brake light stuck to the
rear window since 1990-ish (when they cost >$50 compared with an
incandescant version that was <$10). Also I replaced my offset-pin stop/tail
lamps (BAY15-D or 1157) with LED versions when they first became available
about 10 years ago. I was ordering them from overseas long before they were
available here and have replaced them regularly as better and brighter lamps
come to market.
I also use LED turn indicator lamps for the same reason. They catch the eye
better and can be quite a bit brighter for a fraction of the energy required
to get a metal wire to incandesce.
"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)
Post by bra
And when you are pedalling a costly top fuel at, with sponsors
watching, a red light is really not what you want.