The other day I was taking the bus (which was about 40ft long and
almost fully occupied with other passengers) and the bus was
travelling at roughly 40-45 mph as it was approaching a bus stop (that
typically is vacant). But the driver then suddenly SLAMMED the brakes
as he noticed that someone was waiting at the stop to board. At this
point, all passengers must have felt a noticeable jerk due to the
rapid deceleration involved from the braking. I got off the bus a
couple of stops later and I felt a little dazed for a few hours,
likely due to to his irresponsible braking. I had no headache or
dizziness or disorientation, and I was able to perform all physical or
mental functions well without any effects on my memory, but I'm still
concerned if such rapid deceleration caused by the braking of a large
motor vehicle, can lead to any (temporary or permanent) damage of any
nerve cells in the brain. I read somewhere that the adult human body
should be able to tolerate even a much as 6 G-forces without any risk
or injury and I know that a car or bus brakes, the friction between
the rubber tires and the asphalt pavement isn't sufficient to provide
an immediate stop (such that the overall G-forces felt during braking
could end up being under 1G). But I would certainly appreciate more
accurate and precise information on this matter.

I have already complained to the local public transit authority about
the reckless braking of this driver, which could potentially have
caused other passengers to hit their heads or to stumble or fall, etc.
and/or sustain other injuries. Drivers should realize that they are
serving teh public and should be held accountable for aggressive
driving without regard for the well-being of the public who use their
services and who are, in effect, their clients.

"AliGhas" <alighas2000@hotmail.com> wrote in message
news:fc233106.0307060550.2925421d@posting.google.c om...
Sounds like you're overreacting to me. If you broke a tooth or something on
the seat in front of you I could see being upset. As it is, you got a shot
of adrenaline that resulted in shakey knees and a faster heartrate. I'd say
write it off as the price you pay for using public transportation and move
on.

"Chuck @mindspring.com>" <cbowling<nospam> wrote in message
news:bea624$ovm$2@slb9.atl.mindspring.net...

(...)
I agree. If you really want to see someone with high blood pressure or who
is upset for good reason, you should see the person that the bus driver
misses at a stop, especially if the person is on time and the bus is late.

Jeff

1. most quotes on human G-related tolerance are in the z-axis (ie. the force
acts in a line through the top of your head down your spine and out through
the soles of your feet; or from top of your head and out through your behind
if you are sitting down). This is because most of the work done has been in
relation to tightly turning fighter jets. If my calculations are right, 6G
of 'bus braking' would be going from 22 miles per hour to standstill in one
second. Not very pleasant, much less like braking and much more like hitting
a very solid brick wall.

2. The real risk is not the G itself - it is the tendancy of your body to
keep going when the bus is trying to stop (=inertia). The tighter your body
is coupled to the bus, the less your head/arms/legs/body will move relative
to the bus, the less your body parts will fly forward (relative to the bus),
and the less chance there is that they will hit something hard and painful.
Of course if you're stupid and the bus breaks hard enough - 6 G would
probably do it - you could fly all the way down the centre isle and out of
the front window of the bus - which sounds spectacularly exicting for the
first fraction of a second, closely followed by a world of pain (if you're
lucky).

3. The moral of the story: when on a bus, hold on to something.

Some studies indicate that joy park rides can induce neurologic injury via G
forces. V. low risk though.

--
johnYYYcoe@tpg.com.au

remove YYY in reply
"Ken Catchpole" <k.catchpole@ich.ucl.ac.uk> wrote in message
news:bemlfn$n6a$1@uns-a.ucl.ac.uk...

"AliGhas" <alighas2000@hotmail.com> wrote in message
news:fc233106.0307060550.2925421d@posting.google.c om...
I have been on busses many times during hard braking. The time spent braking
is negligible, unless the subject is suffering from some concurrent
condition such as motion sickness or some other inner ear disorder. If you
felt such disagreeable effects from the busses maneuver, I would strongly
suggest that you seek the council of a qualified physician regarding your
hypersensitivity to deceleratoy forces.

IME, the only time such hard braking on the part of the bus driver resulted
in disagreeable effects was when I was feeling ill.

Joe