Accident statistics

In article ,
"Peter Duniho" wrote:

"Jim Logajan" wrote in message
.. .
In heavy traffic on multi-lane freeways it often happens that when I allow
a decent space between myself and the car in front, drivers in the other
lane will change lanes into the gap I tried to allow. If you keep trying
to
back off to re-acquire the safety gap, the more nature magically puts cars
into it. Eventually you've slowed so much that you're actually driving
backward on the freeway and you end up back where you started.

That is not actually true.

yes it is.

It's a common enough claim by people who don't
want to be bothered to leave the proper distance between them and the car in
front of them,

try leaving 3 seconds around here and some idiot will move into your lane

but it's simply not true.

yes it is.


If traffic is actually backed up,
there is no way for new cars to show up quickly enough to change into your
lane and impede your progress. If the other lane were moving so fast so as
to allow that, the drivers would just stay in their own lane.

not around Boston MA.



I drive in so-called "bumper-to-bumper" traffic far more often than I'd
like, I always leave at *least* two car lengths between me and the car ahead
(even when basically stopped), and more if our speed gets high enough to
warrant it, and I have never ever had any trouble at all keeping up with the
general flow of traffic.

Then you don't have actual bumper-to-bumper.

--
Bob Noel
Looking for a sig the
lawyers will hate

Bob Noel wrote:

try leaving 3 seconds around here and some idiot will move into your lane

I concur. There are rules of thumb and there are rules of locality.
Practical Northeast US metropolitan driving trades protection from rear-end
accidents with more efficient traffic flow.

--
Peter

"Bob Noel" wrote in message
...
If traffic is actually backed up,
there is no way for new cars to show up quickly enough to change into
your
lane and impede your progress. If the other lane were moving so fast so
as
to allow that, the drivers would just stay in their own lane.

not around Boston MA.

It is physically impossible for traffic to behave as you suggest. Even in
Boston. The drivers there are crazy, but they still don't have a free pass
on the laws of physics.

I drive in so-called "bumper-to-bumper" traffic far more often than I'd
like, I always leave at *least* two car lengths between me and the car
ahead
(even when basically stopped), and more if our speed gets high enough to
warrant it, and I have never ever had any trouble at all keeping up with
the
general flow of traffic.

Then you don't have actual bumper-to-bumper.

I put "bumper-to-bumper" in quotes because it seemed to me it would be
obvious to the reader, even you, that if I am leaving a couple of car
lengths in front of me, my car is not literally bumper to bumper with the
car ahead. However, rest assured pretty much all the other drivers are
doing the dumb literal bumper-to-bumper you seem to cherish so much.

Pete

"Peter R." wrote in message
...
I concur. There are rules of thumb and there are rules of locality.
Practical Northeast US metropolitan driving trades protection from
rear-end
accidents with more efficient traffic flow.

Tailgating and efficient traffic flow are mutually exclusive.

In article ,
"Peter Duniho" wrote:

If traffic is actually backed up,
there is no way for new cars to show up quickly enough to change into
your
lane and impede your progress. If the other lane were moving so fast so
as
to allow that, the drivers would just stay in their own lane.

not around Boston MA.

It is physically impossible for traffic to behave as you suggest.

Have you actually seen traffic here?

Even in
Boston. The drivers there are crazy, but they still don't have a free pass
on the laws of physics.

defying laws of physics is not required.


I drive in so-called "bumper-to-bumper" traffic far more often than I'd
like, I always leave at *least* two car lengths between me and the car
ahead
(even when basically stopped), and more if our speed gets high enough to
warrant it, and I have never ever had any trouble at all keeping up with
the
general flow of traffic.

Then you don't have actual bumper-to-bumper.

I put "bumper-to-bumper" in quotes because it seemed to me it would be
obvious to the reader, even you, that if I am leaving a couple of car
lengths in front of me, my car is not literally bumper to bumper with the
car ahead. However, rest assured pretty much all the other drivers are
doing the dumb literal bumper-to-bumper you seem to cherish so much.

Given your obvious lack of experience with of actual bumper-to-bumper
traffic, I can understand your misconceptions.

btw - don't make the mistake of thinking I cherish or enjoy bumper-to-bumper.

--
Bob Noel
Looking for a sig the
lawyers will hate

"Bob Noel" wrote in message
...
Have you actually seen traffic here?

Yes.

defying laws of physics is not required.

Yes, it is. Or are you saying that Boston drivers are so dumb that if they
are in a lane that is passing another lane, they will still switch over to
the slower lane?

Try as you might to convince me you guys are dumb, I'm still not prepared to
believe you're that dumb.

Given your obvious lack of experience with of actual bumper-to-bumper
traffic, I can understand your misconceptions.

Boston, NYC, DC, LA, SF, Chicago, Phoenix, to name a few, I've driven
bumper-to-bumper all over the country. The physics work the same
everywhere, and I've never seen enough drivers so dumb as to switch from a
faster-moving lane to a slower-moving one as to make following at a safe
distance impossible or even impractical, even when the average speed is 5mph
or slower.

Pete

"Peter Duniho" wrote:
"Bob Noel" wrote:
defying laws of physics is not required.

Yes, it is. Or are you saying that Boston drivers are so dumb that if
they are in a lane that is passing another lane, they will still
switch over to the slower lane?

Well ... they may need to exit at the next exit ramp - that normally
requires changing into the slow lane. And I think you're also conflating
the laws of physics with human psychology. But a more fundamental issue is
that the two most common scenarios where I see people changing lanes into
my front "safety gap" is either when traffic in both lanes is traveling
about the same speed or when I am in the fast lane and someone uses my
"safety gap" to enter the fast lane from the slow lane.

I found traveling in the fast lane with the other speeders but trying to
maintain a safe following distance during rush hour in the San Jose
California area was generally difficult. As you point out, drivers in the
fast lane are not inclined to pull into the slow lane unless they have to
(a psychological issue, not a Pauli exclusion principle sort of issue) but
drivers in the slow lane do tend to want to join the fast lane crowd (and
then there are the drivers who seem to constantly switch lanes trying to
find the "fast" one when both lanes are traveling about the same speed).
The result is that safe following distances are sometimes hard to maintain
- at least they were for me.[*]

Try as you might to convince me you guys are dumb, I'm still not
prepared to believe you're that dumb.

I suspect no one here is dumb. Opinionated - yeah. Mistaken sometimes -
well I know have been.
[*] I now work from home - the morning and evening commutes are wonderful.
:-)

"Jim Logajan" wrote in message
.. .
Well ... they may need to exit at the next exit ramp - that normally
requires changing into the slow lane.

The question isn't whether they ever do. The question is whether enough
cars can pull in front of a given driver so as to force him to go backwards
(or even, giving the poster the benefit of the doubt, making him stop).

One car moving through now and then makes no real difference at all.

And I think you're also conflating
the laws of physics with human psychology.

I am, to some extent. What's wrong with that?

My point is that if the lanes are moving at similar speeds, or the lane a
person is in is the faster lane, traffic from the other lane cannot possibly
move into that person's lane fast enough to slow him down significantly.
It's a physical impossibility. The effect drawing all these other supposed
cars into the driver's lane, even if it exists, is self-limiting. If all
these drivers are leaving the one lane for the other, eventually the lane is
going to be travelling so slowly that it is no longer the fast lane.

This means that a person who is claiming an endless stream of people moving
into his own lane is assuming the other lane is moving faster, AND that for
some reason all those drivers moving faster still want to jump in front of
him.

It is both physics and psychology. Thus the conflation.

I have plenty of experience (decades) driving in a wide variety of
congested, urban areas. I have spent my fair share of time stuck in
traffic, traffic equal to any that is relevant to this discussion. And I
have NEVER had any trouble whatsoever leaving sufficient room in front of me
(once I figured out that that was a desireable goal...I admit, I spent a
large portion of my youth tailgating, rushing, worried that other drivers
might get there before me).

It is simply not true that leaving a safe following distance results in an
endless stream of cars blocking one's progress.

Do cars get in front of you? Of course they do. Do the really impatient
people take advantage of the situation and make faster progress relative to
the bulk of traffic? Yes, that's true. Is there any significant increase
in the total trip time for the driver who is allowing a safe following
distance? Absolutely NOT. One might lose a few minutes at most on a 60
minute commute. Big deal.

In any case, I find it absurd that anyone, but a pilot most of all, would
suggest that improving one's trip time is a valid justification for
sacrificing a genuine safety margin as has been claimed here. As long as
traffic isn't backup up, if I drive as fast as I can, weaving back and forth
through traffic, I can easily cut my trip times by 25-30%. That doesn't
justify the action though, nor does cutting a few minutes from one's commute
justify driving unsafely.

But a more fundamental issue is
that the two most common scenarios where I see people changing lanes into
my front "safety gap" is either when traffic in both lanes is traveling
about the same speed or when I am in the fast lane and someone uses my
"safety gap" to enter the fast lane from the slow lane.

Your safety gap is not exclusive to your own use. It is a given that other
drivers will have moments when they need or desire to use it and it is one
of the failings of driving in the US that one driver would begrudge another
of that use. It is, in fact, that gap that makes things MORE efficient so
that traffic can change lanes more freely and without causing the sudden
slowdowns that result in crawling traffic in the first place.

I found traveling in the fast lane with the other speeders but trying to
maintain a safe following distance during rush hour in the San Jose
California area was generally difficult.

I find your analysis interesting, in that it exhibits the very selfishness
that I'm talking about:

As you point out, drivers in the
fast lane are not inclined to pull into the slow lane unless they have to
(a psychological issue, not a Pauli exclusion principle sort of issue) but
drivers in the slow lane do tend to want to join the fast lane crowd

And what is wrong with the drivers in the slow lane wanting to join the fast
lane? If the only reason that the fast lane is a fast lane is because
everyone in that lane has conspired to keep the other vehicles from using
it, that's just selfish behavior.

And if you are concerned that the slow vehicles don't merge into the fast
lane at an appropriate speed (that is, matched with the speed of the lane
itself), well that's just a natural consequence of them tailgating in the
slow lane (that is, engaging in the same unsafe behavior that the drivers in
the fast lane are). They are no different from the drivers in the fast
lane, other than the fact that they haven't managed to get there yet.

(and
then there are the drivers who seem to constantly switch lanes trying to
find the "fast" one when both lanes are traveling about the same speed).

Yup. Sometimes they win, more often they don't. Who cares about them
anyway? It's not like they're hurting anyone other than themselves.

The result is that safe following distances are sometimes hard to maintain
- at least they were for me.[*]

Maintaining a safe following distance is no more challenging than any other
aspect of driving. Does it mean that a driver may now and then pull in
front of you, requiring further adjustment? Sure. So what? Driving on a
public road is a matter of constant adjustments. That's a natural
consequence of sharing a road with other cars.

Does it result in any significant increase in your own trip time? No, it
does not. It's absurd to claim that it does.

Pete

In article ,
"Peter Duniho" wrote:

Have you actually seen traffic here?

Yes.

defying laws of physics is not required.

Yes, it is. Or are you saying that Boston drivers are so dumb that if they
are in a lane that is passing another lane, they will still switch over to
the slower lane?

It would appear that you are confusing laws of physics with lack of common
sense on the part of a number of drivers in the Boston area. In rush hour
traffic (around here at least) it is quite common for one lane to be moving
for a short time and then the other lane to move. Rush hour here never has
one specific lane always moving faster than another. On average, one lane
may make better progress and a lane-switcher may or may not do better
than average. I normally pick a lane and stay with it, and reassess when
the cause of the backup can be determined, but there are other drivers
that seems to be constantly looking to switch lanes.



Try as you might to convince me you guys are dumb, I'm still not prepared to
believe you're that dumb.

Not everyone has to be dumb, just a minority of inconsiderate folks in a hurry
driving in manner that lacks common sense.



Given your obvious lack of experience with of actual bumper-to-bumper
traffic, I can understand your misconceptions.

Boston, NYC, DC, LA, SF, Chicago, Phoenix, to name a few, I've driven
bumper-to-bumper all over the country.

Yet you've never seen people switching lanes? That's hard to believe.

The physics work the same
everywhere,

There are no laws of physics that apply to common sense.


and I've never seen enough drivers so dumb as to switch from a
faster-moving lane to a slower-moving one as to make following at a safe
distance impossible or even impractical, even when the average speed is 5mph
or slower.

Yet you say you've driven in Boston.

--
Bob Noel
Looking for a sig the
lawyers will hate

Dan:

Remember, these figures http://www.ntsb.gov/aviation/Table10.htm are
based on "Flight Hours", which are different from "Air Hours" (at least
where I'm from in Canada). For small aircraft flight hours start at
the time the electrical system of the plane is started, to when it is
shut off, and the AC is no longer moving.

In essence what this means is that all the time the aircraft is being
operated in any way, even on the ground, are included in "Flight
Hours". If any power source in the plane is operational (or the AC is
moving with a person on board), then this is counted as a Flight Hour.
Thus, all ground accidents, such as those where people walk into moving
propellers, and taxiing accidents, are included here.

There are a considerable number of fatal accidents involving small AC
on the ground, most of which are due to carelessness, or unkowledgable
people being allowed to walk too close to an operating AC.

On the other hand, "Air Hours" are those hours that the AC spends from
the time its wheels leave the ground to the time they (hopefully
extended) touch down again.

During flight training operations non-Air Hours can make up a
considerable portion of the Flight Hours (For instance, during my
training flights as much as 20% of my "Flight Hours" were not "Air
Hours", so this fact should be taken into account when looking at these
accident figures.).

One conclusion to be drawn is that these rates include accidents on the
ground involving AC powered in any way, or moving in any way with a
person on board.

I don't know if this will serve to comfort your wife at all however ...


I am unsure if there are stats anywhere that remove the accidents that
occur during non Air Hours. These would give a more accurate idea of
the danger involved in flying, as opposed to the danger of being around
operating and dangerous equipment, which, when you think about it, is
all an AC is when it is on the ground and running - a dangerous
machine, but not essentially different from working with any number of
other large machines with rapidly moving parts.

PPL-A


Dan wrote:
So, based on these numbers, I have a 1.3% chance of a fatal accident
before I reach 1000 hours. Wow, that is a bit high....

My mother recently died in a motorcycle accident, and that brings the
risk of such things a bit closer to home if you know what I mean...

--Dan


Dan Luke wrote:
"Marc Adler" wrote:


As you have probably guessed, this information is for calming a wife's
worry about her husband's burgeoning interest in flying...

If that's what you're after, you probably won't like what you find.

--
Dan
C172RG at BFM