> On the other hand, that still gives up a lot of flexibility and
> convenience I'm very much used to.
Precisely. Although I live very close to where a number of buses stop, unless I want to go to the city, not one of them goes anywhere where I want to go. Add to that the waiting, the many buses that don't turn up at all, the having to change buses to get anywhere useful... and if you don't live near a bus stop as I do, then you may have to drive to one and spend ages looking for somewhere to park.
In rec.arts.sf.written Your Name <YourN...@yourisp.com> wrote:
> Cars on the other hand are alweays carrying at least one passenger to
> somewhere they want to go (even if that trip may seem unneccesary to other
> people).
I wouldn't normally classify the driver of a returning taxi as a
passenger going somewhere they want to go. At least no more so than a
bus-driver. And a mother picking up her kids at soccer practice is, in
this context, the same as an unpaid taxi driver.
> In article
> <9d740523-39e3-4f6b-bb8b-69c759e6a...@z38g2000vbu.googlegroups.com>,
> Cryptoengineer <petert...@gmail.com> wrote:
> > On Apr 11, 11:59 am, David Dyer-Bennet <d...@dd-b.net> wrote:
> > > Suzanne Blom <bo...@sueblom.net> writes:
> > > > On 4/6/2012 7:10 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > >> On 4/6/12 6:28 PM, Suzanne Blom wrote:
> > > >>> On 4/5/2012 4:03 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > >>>> On 4/5/12 4:55 PM, Suzanne Blom wrote:
> > > >>>>> On 4/4/2012 9:13 AM, David Dyer-Bennet wrote:
> > > >>>>>> Suzanne Blom<bo...@sueblom.net> writes:
> > > >>>>>>> I like public mass transit, which among other things, uses less gas
> > > >>>>>>> and road space per person. And is one of the few places where
> > > >>>>>>> people
> > > >>>>>>> mingle with those not like themselves.
> > > >>>>>> I really don't like it that well; it wastes my time at a huge rate,
> > > >>>>>> generally 2:1 compared to driving. It often doesn't go where I need
> > > >>>>>> to
> > > >>>>>> go. It requires standing around in the pouring rain (or the -20F
> > > >>>>>> plus
> > > >>>>>> windchill cold) waiting for a bus that will be late or not come at
> > > >>>>>> all
> > > >>>>>> or be too full to pick me up. It makes me constantly nervous about
> > > >>>>>> not
> > > >>>>>> missing the last bus out. And it doesn't let me read or do anything
> > > >>>>>> else nearly as often as I want (in winter it's often too cold and
> > > >>>>>> we're
> > > >>>>>> too bundled up for even the limited movement of getting a book out
> > > >>>>>> of a
> > > >>>>>> bag, other times it's too crowded to get a seat, etc. Forget about
> > > >>>>>> taking out even a small tablet computer and doing anything with
> > > >>>>>> that.).
> > > >>>>>> And it's hideously expensive to build and run.
> > > >>>>> On the busses I ride, I often see people doing homework, etc. If
> > > >>>>> busses
> > > >>>>> are overcrowded I assume they're popular.
> > > >>>> Filled with those who have no alternative, and as the number of them
> > > >>>> are
> > > >>>> limited, crammed to capacity. Sometimes beyond.
> > > >>>>> And I'd love to see statistics showing they cost more than cars to
> > > >>>>> get
> > > >>>>> around in. Um,not in a fantasy story.
> > > >>>> How do you want to calculate the costs? That will determine your
> > > >>>> answer?
> > > >>>> For instance, taking a bus would, as the prior poster mentions, cost
> > > >>>> me
> > > >>>> oodles of time. Probably 2 hours versus 20 minutes. Do you count the
> > > >>>> cost of my time lost? (if you don't, as far as I'm concerned the
> > > >>>> calculations are useless)
> > > >>>> There's also the assumptions of how many buses and how frequently they
> > > >>>> run, versus the ridership, the number of routes, etc.; how much
> > > >>>> maintenance costs (estimates versus actual) and a lot of other
> > > >>>> factors.
> > > >>> And, of course, for car drivers, the cost of building bigger roads with
> > > >>> more traffic lights, signage, and so on.
> > > >> You need to build more roads for buses. Or rip up roads and replace them
> > > >> with railroad tracks, for rail.
> > > >> Remember, installing nice public transport? Doesn't make the cars go
> > > >> away. Even if EVENTUALLY there will be a reduction, it won't happen
> > > >> immediately, or even in the next several months. A few people will
> > > >> switch right away. If they have good experiences and the system runs
> > > >> smoothly, more people will switch after a few months, then a few more.
> > > >> Some (like myself) will almost certainly never switch.
> > > >> So if you want to IMPROVE (rather than reduce) throughput, you have to
> > > >> put *ADDITIONAL* capacity into the roads in order to handle the
> > > >> considerably increase caused by buses (since they stop frequently, if
> > > >> you don't add more lanes, they will actually make things WORSE at least
> > > >> in the beginning because they will pile traffic up behind them.
> > > > One of the things I was trying to point out is the automatic
> > > > assumption that cars have first dibs always.
> > > > New York City doesn't have that assumption, millions upon millions of
> > > > people move around it every day without cars, and it's one of the
> > > > movers and shakers of the whole world. The assumption seems to be
> > > > that because it's big, it can have working mass transit; I suspect,
> > > > though, that part of the reason it's big is because, with the mass
> > > > transit, one can fit more people in. And, oh yeah, not that much road
> > > > space used since most of it is underground.
> > > I suspect it's even harder to replicate. I'm pretty sure the real
> > > factor was that NYC was big enough and dense enough to support mass
> > > transit more than *100 years ago*. (IRT service seems to have started
> > > in 1905. That may well not have been the first mass transit in NYC.)
> > It wasn't. The first elevated line, was the 9th avenue EL, from the
> > Battery to the Bronx, opened in 1868 (5 years after the first part of
> > the London Underground opened). It later became part of the IRT.
> > pt
> So that explains the dreams I have of an elevated train running up the
> West Side.
Of course, the #1 is still elevated at 125th street, where it crosses
a valley, and north of Dyckman/200th.
In article <FMidnbNu_NlBRhbSnZ2dnUVZ7tWdn...@giganews.com>, Leif Roar
Moldskred <le...@dimnakorr.com> wrote:
> In rec.arts.sf.written Your Name <YourN...@yourisp.com> wrote:
> > Cars on the other hand are alweays carrying at least one passenger to
> > somewhere they want to go (even if that trip may seem unneccesary to other
> > people).
> I wouldn't normally classify the driver of a returning taxi as a
> passenger going somewhere they want to go. At least no more so than a
> bus-driver. And a mother picking up her kids at soccer practice is, in
> this context, the same as an unpaid taxi driver.
I meant private cars, not taxis ... but even then a "taxi" (normal or
unpaid) weighs less, takes up less room on the road, doesn't belch out
large amounts of diesel smoke, etc. like an empty bus, and in terms of the
unpaid "taxi" is still going where the person driving wants to go.
Cryptoengineer <petert...@gmail.com> wrote:
> On Apr 15, 3:55 pm, Walter Bushell <pr...@panix.com> wrote:
> > In article
> > <9d740523-39e3-4f6b-bb8b-69c759e6a...@z38g2000vbu.googlegroups.com>,
> > Cryptoengineer <petert...@gmail.com> wrote:
> > > On Apr 11, 11:59 am, David Dyer-Bennet <d...@dd-b.net> wrote:
> > > > Suzanne Blom <bo...@sueblom.net> writes:
> > > > > On 4/6/2012 7:10 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > > >> On 4/6/12 6:28 PM, Suzanne Blom wrote:
> > > > >>> On 4/5/2012 4:03 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > > >>>> On 4/5/12 4:55 PM, Suzanne Blom wrote:
> > > > >>>>> On 4/4/2012 9:13 AM, David Dyer-Bennet wrote:
> > > > >>>>>> Suzanne Blom<bo...@sueblom.net> writes:
> > > > >>>>>>> I like public mass transit, which among other things, uses less > > > > >>>>>>> gas
> > > > >>>>>>> and road space per person. And is one of the few places where
> > > > >>>>>>> people
> > > > >>>>>>> mingle with those not like themselves.
> > > > >>>>>> I really don't like it that well; it wastes my time at a huge > > > > >>>>>> rate,
> > > > >>>>>> generally 2:1 compared to driving. It often doesn't go where I > > > > >>>>>> need
> > > > >>>>>> to
> > > > >>>>>> go. It requires standing around in the pouring rain (or the -20F
> > > > >>>>>> plus
> > > > >>>>>> windchill cold) waiting for a bus that will be late or not come > > > > >>>>>> at
> > > > >>>>>> all
> > > > >>>>>> or be too full to pick me up. It makes me constantly nervous > > > > >>>>>> about
> > > > >>>>>> not
> > > > >>>>>> missing the last bus out. And it doesn't let me read or do > > > > >>>>>> anything
> > > > >>>>>> else nearly as often as I want (in winter it's often too cold > > > > >>>>>> and
> > > > >>>>>> we're
> > > > >>>>>> too bundled up for even the limited movement of getting a book > > > > >>>>>> out
> > > > >>>>>> of a
> > > > >>>>>> bag, other times it's too crowded to get a seat, etc. Forget > > > > >>>>>> about
> > > > >>>>>> taking out even a small tablet computer and doing anything with
> > > > >>>>>> that.).
> > > > >>>>>> And it's hideously expensive to build and run.
> > > > >>>>> On the busses I ride, I often see people doing homework, etc. If
> > > > >>>>> busses
> > > > >>>>> are overcrowded I assume they're popular.
> > > > >>>> Filled with those who have no alternative, and as the number of > > > > >>>> them
> > > > >>>> are
> > > > >>>> limited, crammed to capacity. Sometimes beyond.
> > > > >>>>> And I'd love to see statistics showing they cost more than cars > > > > >>>>> to
> > > > >>>>> get
> > > > >>>>> around in. Um,not in a fantasy story.
> > > > >>>> How do you want to calculate the costs? That will determine your
> > > > >>>> answer?
> > > > >>>> For instance, taking a bus would, as the prior poster mentions, > > > > >>>> cost
> > > > >>>> me
> > > > >>>> oodles of time. Probably 2 hours versus 20 minutes. Do you count > > > > >>>> the
> > > > >>>> cost of my time lost? (if you don't, as far as I'm concerned the
> > > > >>>> calculations are useless)
> > > > >>>> There's also the assumptions of how many buses and how frequently > > > > >>>> they
> > > > >>>> run, versus the ridership, the number of routes, etc.; how much
> > > > >>>> maintenance costs (estimates versus actual) and a lot of other
> > > > >>>> factors.
> > > > >>> And, of course, for car drivers, the cost of building bigger roads > > > > >>> with
> > > > >>> more traffic lights, signage, and so on.
> > > > >> You need to build more roads for buses. Or rip up roads and replace > > > > >> them
> > > > >> with railroad tracks, for rail.
> > > > >> Remember, installing nice public transport? Doesn't make the cars go
> > > > >> away. Even if EVENTUALLY there will be a reduction, it won't happen
> > > > >> immediately, or even in the next several months. A few people will
> > > > >> switch right away. If they have good experiences and the system runs
> > > > >> smoothly, more people will switch after a few months, then a few > > > > >> more.
> > > > >> Some (like myself) will almost certainly never switch.
> > > > >> So if you want to IMPROVE (rather than reduce) throughput, you have > > > > >> to
> > > > >> put *ADDITIONAL* capacity into the roads in order to handle the
> > > > >> considerably increase caused by buses (since they stop frequently, > > > > >> if
> > > > >> you don't add more lanes, they will actually make things WORSE at > > > > >> least
> > > > >> in the beginning because they will pile traffic up behind them.
> > > > > One of the things I was trying to point out is the automatic
> > > > > assumption that cars have first dibs always.
> > > > > New York City doesn't have that assumption, millions upon millions of
> > > > > people move around it every day without cars, and it's one of the
> > > > > movers and shakers of the whole world. The assumption seems to be
> > > > > that because it's big, it can have working mass transit; I suspect,
> > > > > though, that part of the reason it's big is because, with the mass
> > > > > transit, one can fit more people in. And, oh yeah, not that much > > > > > road
> > > > > space used since most of it is underground.
> > > > I suspect it's even harder to replicate. I'm pretty sure the real
> > > > factor was that NYC was big enough and dense enough to support mass
> > > > transit more than *100 years ago*. (IRT service seems to have started
> > > > in 1905. That may well not have been the first mass transit in NYC.)
> > > It wasn't. The first elevated line, was the 9th avenue EL, from the
> > > Battery to the Bronx, opened in 1868 (5 years after the first part of
> > > the London Underground opened). It later became part of the IRT.
> > > pt
> > So that explains the dreams I have of an elevated train running up the
> > West Side.
> Of course, the #1 is still elevated at 125th street, where it crosses
> a valley, and north of Dyckman/200th.
> pt
Well the dreams I had it ran from at least 34th street up to and past the boat basin at 79th Street and these dreams were from before I became familiar with the elevated part of the #1 of the Irritating Transit Lines.
> In article
> <e5d0d273-3013-484b-bfa7-7aa5677b3...@l4g2000vbt.googlegroups.com>,
> Cryptoengineer <petert...@gmail.com> wrote:
> > On Apr 15, 3:55 pm, Walter Bushell <pr...@panix.com> wrote:
> > > In article
> > > <9d740523-39e3-4f6b-bb8b-69c759e6a...@z38g2000vbu.googlegroups.com>,
> > > Cryptoengineer <petert...@gmail.com> wrote:
> > > > On Apr 11, 11:59 am, David Dyer-Bennet <d...@dd-b.net> wrote:
> > > > > Suzanne Blom <bo...@sueblom.net> writes:
> > > > > > On 4/6/2012 7:10 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > > > >> On 4/6/12 6:28 PM, Suzanne Blom wrote:
> > > > > >>> On 4/5/2012 4:03 PM, Sea Wasp (Ryk E. Spoor) wrote:
> > > > > >>>> On 4/5/12 4:55 PM, Suzanne Blom wrote:
> > > > > >>>>> On 4/4/2012 9:13 AM, David Dyer-Bennet wrote:
> > > > > >>>>>> Suzanne Blom<bo...@sueblom.net> writes:
> > > > > >>>>>>> I like public mass transit, which among other things, uses less
> > > > > >>>>>>> gas
> > > > > >>>>>>> and road space per person. And is one of the few places where
> > > > > >>>>>>> people
> > > > > >>>>>>> mingle with those not like themselves.
> > > > > >>>>>> I really don't like it that well; it wastes my time at a huge
> > > > > >>>>>> rate,
> > > > > >>>>>> generally 2:1 compared to driving. It often doesn't go where I
> > > > > >>>>>> need
> > > > > >>>>>> to
> > > > > >>>>>> go. It requires standing around in the pouring rain (or the -20F
> > > > > >>>>>> plus
> > > > > >>>>>> windchill cold) waiting for a bus that will be late or not come
> > > > > >>>>>> at
> > > > > >>>>>> all
> > > > > >>>>>> or be too full to pick me up. It makes me constantly nervous
> > > > > >>>>>> about
> > > > > >>>>>> not
> > > > > >>>>>> missing the last bus out. And it doesn't let me read or do
> > > > > >>>>>> anything
> > > > > >>>>>> else nearly as often as I want (in winter it's often too cold
> > > > > >>>>>> and
> > > > > >>>>>> we're
> > > > > >>>>>> too bundled up for even the limited movement of getting a book
> > > > > >>>>>> out
> > > > > >>>>>> of a
> > > > > >>>>>> bag, other times it's too crowded to get a seat, etc. Forget
> > > > > >>>>>> about
> > > > > >>>>>> taking out even a small tablet computer and doing anything with
> > > > > >>>>>> that.).
> > > > > >>>>>> And it's hideously expensive to build and run.
> > > > > >>>>> On the busses I ride, I often see people doing homework, etc. If
> > > > > >>>>> busses
> > > > > >>>>> are overcrowded I assume they're popular.
> > > > > >>>> Filled with those who have no alternative, and as the number of
> > > > > >>>> them
> > > > > >>>> are
> > > > > >>>> limited, crammed to capacity. Sometimes beyond.
> > > > > >>>>> And I'd love to see statistics showing they cost more than cars
> > > > > >>>>> to
> > > > > >>>>> get
> > > > > >>>>> around in. Um,not in a fantasy story.
> > > > > >>>> How do you want to calculate the costs? That will determine your
> > > > > >>>> answer?
> > > > > >>>> For instance, taking a bus would, as the prior poster mentions,
> > > > > >>>> cost
> > > > > >>>> me
> > > > > >>>> oodles of time. Probably 2 hours versus 20 minutes. Do you count
> > > > > >>>> the
> > > > > >>>> cost of my time lost? (if you don't, as far as I'm concerned the
> > > > > >>>> calculations are useless)
> > > > > >>>> There's also the assumptions of how many buses and how frequently
> > > > > >>>> they
> > > > > >>>> run, versus the ridership, the number of routes, etc.; how much
> > > > > >>>> maintenance costs (estimates versus actual) and a lot of other
> > > > > >>>> factors.
> > > > > >>> And, of course, for car drivers, the cost of building bigger roads
> > > > > >>> with
> > > > > >>> more traffic lights, signage, and so on.
> > > > > >> You need to build more roads for buses. Or rip up roads and replace
> > > > > >> them
> > > > > >> with railroad tracks, for rail.
> > > > > >> Remember, installing nice public transport? Doesn't make the cars go
> > > > > >> away. Even if EVENTUALLY there will be a reduction, it won't happen
> > > > > >> immediately, or even in the next several months. A few people will
> > > > > >> switch right away. If they have good experiences and the system runs
> > > > > >> smoothly, more people will switch after a few months, then a few
> > > > > >> more.
> > > > > >> Some (like myself) will almost certainly never switch.
> > > > > >> So if you want to IMPROVE (rather than reduce) throughput, you have
> > > > > >> to
> > > > > >> put *ADDITIONAL* capacity into the roads in order to handle the
> > > > > >> considerably increase caused by buses (since they stop frequently,
> > > > > >> if
> > > > > >> you don't add more lanes, they will actually make things WORSE at
> > > > > >> least
> > > > > >> in the beginning because they will pile traffic up behind them.
> > > > > > One of the things I was trying to point out is the automatic
> > > > > > assumption that cars have first dibs always.
> > > > > > New York City doesn't have that assumption, millions upon millions of
> > > > > > people move around it every day without cars, and it's one of the
> > > > > > movers and shakers of the whole world. The assumption seems to be
> > > > > > that because it's big, it can have working mass transit; I suspect,
> > > > > > though, that part of the reason it's big is because, with the mass
> > > > > > transit, one can fit more people in. And, oh yeah, not that much
> > > > > > road
> > > > > > space used since most of it is underground.
> > > > > I suspect it's even harder to replicate. I'm pretty sure the real
> > > > > factor was that NYC was big enough and dense enough to support mass
> > > > > transit more than *100 years ago*. (IRT service seems to have started
> > > > > in 1905. That may well not have been the first mass transit in NYC.)
> > > > It wasn't. The first elevated line, was the 9th avenue EL, from the
> > > > Battery to the Bronx, opened in 1868 (5 years after the first part of
> > > > the London Underground opened). It later became part of the IRT.
> > > > pt
> > > So that explains the dreams I have of an elevated train running up the
> > > West Side.
> > Of course, the #1 is still elevated at 125th street, where it crosses
> > a valley, and north of Dyckman/200th.
> > pt
> Well the dreams I had it ran from at least 34th street up to and past
> the boat basin at 79th Street and these dreams were from before I
> became familiar with the elevated part of the #1 of the Irritating
> Transit Lines.
>>> What would a self-driving car do when a road is temporarily
>>> obstructed due to construction work, and a police officer is
>>> detouring traffic manually? Just plow right into him?
>>> -- Steven L.
>> The same thing they'd do if someone runs out into the street or
>> if a car is simply parked in the middle of the street--detour.
>> It's not like this is some insurmountable or even unimaginable
>> problem. Basic video cameras could detect the police officer,
>> or construction worker, or just a regular person in the middle
>> of the street and scan their gesturing in a certain direction
>> and go in the direction, recalculating the path back to its
>> destination.
> Don't forget it must also be able to distinguish between a
> police officer and a drunken moron - not always easy even for
> humans.
I would think that it would want to avoid both equally well.
-- Terry Austin
"Terry Austin: like the polio vaccine, only with more asshole."
-- David Bilek
YourN...@YourISP.com (Your Name) wrote:
>For a start, a bus can only drive on one area of road with all four (or
>more) tyres. It's highly unlikely that 20 cars will drive on the exactly
>the same area of the road - one will be slightly more left, one will be
>slightly more right, one will turn slightly earlier, one will turn
>slightly later, etc.
But one bus won't destroy the road. Once you have more than one, the
same thing happens with the buses.
I heard somewhere that when airplanes started using GPS-guided
landings, they started beating the hell out of runways at exactly the
same point every time.
-- I used to own a mind like a steel trap.
Perhaps if I'd specified a brass one, it
wouldn't have rusted like this.
In article <9vls1tFtj...@mid.individual.net>, go...@gossg.org wrote:
> YourN...@YourISP.com (Your Name) wrote:
> >For a start, a bus can only drive on one area of road with all four (or
> >more) tyres. It's highly unlikely that 20 cars will drive on the exactly
> >the same area of the road - one will be slightly more left, one will be
> >slightly more right, one will turn slightly earlier, one will turn
> >slightly later, etc.
> But one bus won't destroy the road. Once you have more than one, the
> same thing happens with the buses.
The question was whether ONE bus creates more damage than the 20 cars it
supposedly replaces.
Of course if you have 10 buses they will create more damage than one bus,
they'll also create more damage than the 200 cars they supposedly replace.
> I heard somewhere that when airplanes started using GPS-guided
> landings, they started beating the hell out of runways at exactly the
> same point every time.
Which is yet another problem that self-drive vehicles (cars, buses,
trucks, etc.) will create ... one of many that the people in charge
haven't even remotely thought about.
YourN...@YourISP.com (Your Name) writes:
> In article <9vls1tFtj...@mid.individual.net>, go...@gossg.org wrote:
>> I heard somewhere that when airplanes started using GPS-guided
>> landings, they started beating the hell out of runways at exactly the
>> same point every time.
> Which is yet another problem that self-drive vehicles (cars, buses,
> trucks, etc.) will create ... one of many that the people in charge
> haven't even remotely thought about.
Well, I don't know if the airplane story is actually true; he just heard
it somewhere. It does have a kind of basic believability, certainly.
David Dyer-Bennet <d...@dd-b.net> wrote:
>YourN...@YourISP.com (Your Name) writes:
>> In article <9vls1tFtj...@mid.individual.net>, go...@gossg.org wrote:
>>> I heard somewhere that when airplanes started using GPS-guided
>>> landings, they started beating the hell out of runways at exactly the
>>> same point every time.
>> Which is yet another problem that self-drive vehicles (cars, buses,
>> trucks, etc.) will create ... one of many that the people in charge
>> haven't even remotely thought about.
Quite the contrary - as it's very unlikely a self drive vehicle will
be allowed on the road w/o proximity sensor to avoid other vehicles.
>Well, I don't know if the airplane story is actually true; he just heard
>it somewhere. It does have a kind of basic believability, certainly.
I saw it cited in the RISKS digest years ago. The other problem cited
WRT GPS and airplanes is that GPS autonavigators try to fly the center
of the corridor, where in the 'old days' natural navigation errors
dispersed them across the corridor.
>The extreme case of this of course is trains, which require you to build
>very special tracks, but at least properly built tracks do support the
>load properly.
But how the tracks are built is important too.... The weight of the
rail, the type of attachment to the tie, and the type/condition of the
roadbed all go into determining the safe speed and loading of trains
that can travel across it.
> >> In article <9vls1tFtj...@mid.individual.net>, go...@gossg.org wrote:
> >>> I heard somewhere that when airplanes started using GPS-guided
> >>> landings, they started beating the hell out of runways at exactly the
> >>> same point every time.
> >> Which is yet another problem that self-drive vehicles (cars, buses,
> >> trucks, etc.) will create ... one of many that the people in charge
> >> haven't even remotely thought about.
> Quite the contrary - as it's very unlikely a self drive vehicle will
> be allowed on the road w/o proximity sensor to avoid other vehicles.
Errr ... we were talking about the airplanes or self-drive cars following
exactly the same path along the runway / road wearing it away. It has
nothing to do with avoiding anything (other than potholes).
> >Well, I don't know if the airplane story is actually true; he just heard
> >it somewhere. It does have a kind of basic believability, certainly.
> I saw it cited in the RISKS digest years ago. The other problem cited
> WRT GPS and airplanes is that GPS autonavigators try to fly the center
> of the corridor, where in the 'old days' natural navigation errors
> dispersed them across the corridor.
> >The extreme case of this of course is trains, which require you to build
> >very special tracks, but at least properly built tracks do support the
> >load properly.
> But how the tracks are built is important too.... The weight of the
> rail, the type of attachment to the tie, and the type/condition of the
> roadbed all go into determining the safe speed and loading of trains
> that can travel across it.
And well-used tracks do have to be repaired relatively often.
> I heard somewhere that when airplanes started using GPS-guided
> landings, they started beating the hell out of runways at exactly the
> same point every time.
That's vaguely sorta plausible for airplanes, which have a pretty wide footprint; but in actual navigation contexts (as opposed to roadway driving where they cheat shamelessly), the accuracy is going to be +/- a meter (or considerably more), which is a lot wider than the tires, so they're not going to actually hit the same point. But they may well be grouping more tightly than previously.
For anything on roadways, it won't matter; a meter-level accuracy is about as much variation as you can manage on a normal lane anyway.
> David Dyer-Bennet<d...@dd-b.net> wrote:
>> The extreme case of this of course is trains, which require you to build
>> very special tracks, but at least properly built tracks do support the
>> load properly.
> But how the tracks are built is important too.... The weight of the
> rail, the type of attachment to the tie, and the type/condition of the
> roadbed all go into determining the safe speed and loading of trains
> that can travel across it.
And they still wear out -- quite significantly. And a track built to designs 20 or 30 years ago isn't really built to handle modern trains which have steadily increased in load; where a large carload in 1970 might have been 125,000 pounds, many cars now are hitting 300,000 pounds, which means axle loads are WAY up.
> >For a start, a bus can only drive on one area of road with all four (or
> >more) tyres. It's highly unlikely that 20 cars will drive on the exactly
> >the same area of the road - one will be slightly more left, one will be
> >slightly more right, one will turn slightly earlier, one will turn
> >slightly later, etc.
> But one bus won't destroy the road. Once you have more than one, the
> same thing happens with the buses.
> I heard somewhere that when airplanes started using GPS-guided
> landings, they started beating the hell out of runways at exactly the
> same point every time.
And two aircraft in South America collided head on, because of the recent perfection of automatic navigation and a failure to keep proper altitude.
<http://www.vanityfair.com/magazine/2009/01/air_crash200901>
The airplanes closed at a combined airspeed of 1,000 miles an hour. At that velocity, a distant airplane--a speck on the horizon--will fill the windshield in a matter of seconds. Photo illustration by Chris Mueller. By Gerd Ludwig/Visum/The Image Works (Amazon), from Reuters/Landov (plane), by Chad Slattery (cockpit).
In article <4f95d22d.278713...@news.supernews.com>, fairwa...@gmail.com
(Derek Lyons) wrote:
[snip]
>I saw it cited in the RISKS digest years ago. The other problem cited
>WRT GPS and airplanes is that GPS autonavigators try to fly the center
>of the corridor, where in the 'old days' natural navigation errors
>dispersed them across the corridor.
[snip]
One thing I read was that for areas of the country that are not in the
immeidate area of an airport, it would be possible to eliminate the flight
corridors and let airplanes fly whereever the pilots wanted to. That there
would be less likelyhood of a mid-air collision that exists with the
corridors in place.
>> I heard somewhere that when airplanes started using GPS-guided
>> landings, they started beating the hell out of runways at exactly the
>> same point every time.
> That's vaguely sorta plausible for airplanes, which have a pretty wide >footprint; but in actual navigation contexts (as opposed to roadway >driving where they cheat shamelessly), the accuracy is going to be +/- a >meter (or considerably more), which is a lot wider than the tires, so >they're not going to actually hit the same point. But they may well be >grouping more tightly than previously.
Perhaps for the airplanes, "the same point" is many meters square, rather
than just the footprint (tireprint) of the tires on the plane. The weight
of the plane could damage this larger area with more landings in the same
area, rather than spreading the landing sites further along the runway.
> For anything on roadways, it won't matter; a meter-level accuracy is >about as much variation as you can manage on a normal lane anyway.
><http://www.vanityfair.com/magazine/2009/01/air_crash200901>
>The airplanes closed at a combined airspeed of 1,000 miles an hour. At >that velocity, a distant airplane--a speck on the horizon--will fill the >windshield in a matter of seconds. Photo illustration by Chris >Mueller. By Gerd Ludwig/Visum/The Image Works (Amazon), from >Reuters/Landov (plane), by Chad Slattery (cockpit).
>>I saw it cited in the RISKS digest years ago. The other problem cited
>>WRT GPS and airplanes is that GPS autonavigators try to fly the center
>>of the corridor, where in the 'old days' natural navigation errors
>>dispersed them across the corridor.
>[snip]
>One thing I read was that for areas of the country that are not in the
>immeidate area of an airport, it would be possible to eliminate the flight
>corridors and let airplanes fly whereever the pilots wanted to.
RNAV 2 is the current method of allowing the airline some flexibility
in the routing.
No, pilots will never "fly whereevery they want". The flight route plan
is carefully designed for fuel efficiency and is based on a number of factors
including weather/jetstream, etc.
Regardless, constant surveillance of the airspace by the FAA is used to
deconflict any potential separation violations.
>That there
>would be less likelyhood of a mid-air collision that exists with the
>corridors in place.
Not likely. When, in fact, was the last non-VFR mid-air?
>> >> In article <9vls1tFtj...@mid.individual.net>, go...@gossg.org wrote:
>> >>> I heard somewhere that when airplanes started using GPS-guided
>> >>> landings, they started beating the hell out of runways at exactly the
>> >>> same point every time.
>> >> Which is yet another problem that self-drive vehicles (cars, buses,
>> >> trucks, etc.) will create ... one of many that the people in charge
>> >> haven't even remotely thought about.
>> Quite the contrary - as it's very unlikely a self drive vehicle will
>> be allowed on the road w/o proximity sensor to avoid other vehicles.
>Errr ... we were talking about the airplanes or self-drive cars following
>exactly the same path along the runway / road wearing it away. It has
>nothing to do with avoiding anything (other than potholes).
Well, that's not that much of a problem - 90%+ of the cars are dang
near in the same tracks anyhow.
>>> The extreme case of this of course is trains, which require you to build
>>> very special tracks, but at least properly built tracks do support the
>>> load properly.
>> But how the tracks are built is important too.... The weight of the
>> rail, the type of attachment to the tie, and the type/condition of the
>> roadbed all go into determining the safe speed and loading of trains
>> that can travel across it.
> And they still wear out -- quite significantly. And a track built to >designs 20 or 30 years ago isn't really built to handle modern trains >which have steadily increased in load; where a large carload in 1970 >might have been 125,000 pounds, many cars now are hitting 300,000 >pounds, which means axle loads are WAY up.
Since locomotives can weight upwards of 400,000 lbs... I'm not sure
that 300,000 lb cargo cars are that big an issue. Not that there's
much track left from 20 or 30 years ago I suspect, railroads routinely
spend seriously big bucks upgrading and maintaining their tracks.
> "Sea Wasp (Ryk E. Spoor)"<seaw...@sgeinc.invalid.com> wrote:
>> On 4/23/12 6:12 PM, Derek Lyons wrote:
>>> David Dyer-Bennet<d...@dd-b.net> wrote:
>>>> The extreme case of this of course is trains, which require you to build
>>>> very special tracks, but at least properly built tracks do support the
>>>> load properly.
>>> But how the tracks are built is important too.... The weight of the
>>> rail, the type of attachment to the tie, and the type/condition of the
>>> roadbed all go into determining the safe speed and loading of trains
>>> that can travel across it.
>> And they still wear out -- quite significantly. And a track built to
>> designs 20 or 30 years ago isn't really built to handle modern trains
>> which have steadily increased in load; where a large carload in 1970
>> might have been 125,000 pounds, many cars now are hitting 300,000
>> pounds, which means axle loads are WAY up.
> Since locomotives can weight upwards of 400,000 lbs... I'm not sure
> that 300,000 lb cargo cars are that big an issue.
One 400,000 pound locomotive may be dragging 100 cars. Yes, it's a BIG issue when those hundred cars are twice the weight you assumed they would be.
> Not that there's
> much track left from 20 or 30 years ago I suspect, railroads routinely
> spend seriously big bucks upgrading and maintaining their tracks.
They replace track, mostly, and fill in/maintain the ties and ballast. Upgrading the design, that's much less common, and much harder to do.
"Sea Wasp (Ryk E. Spoor)" <seaw...@sgeinc.invalid.com> wrote:
>On 4/27/12 1:43 AM, Derek Lyons wrote:
>>> And they still wear out -- quite significantly. And a track built to
>>> designs 20 or 30 years ago isn't really built to handle modern trains
>>> which have steadily increased in load; where a large carload in 1970
>>> might have been 125,000 pounds, many cars now are hitting 300,000
>>> pounds, which means axle loads are WAY up.
>> Since locomotives can weight upwards of 400,000 lbs... I'm not sure
>> that 300,000 lb cargo cars are that big an issue.
> One 400,000 pound locomotive may be dragging 100 cars. Yes, it's a BIG >issue when those hundred cars are twice the weight you assumed they >would be.
I stalled a train once. Or rather a program that I'd inherited the
charge of (which should have been put out of its misery long before
going live) was miscalculating the weight of TOFC when two short
trailers were put into one long-trailer space. The program calculated
the weight of both trailers, but put the second weight over the first
and left the second trailer weight at zero. Then summed up the
trailers on each car that our operation were providing to the train
and handed that to the car marshalling software, which decided how
many locomotives (and which ones) to use.
oops.
We inherited the source code when a software company failed to deliver
on a promised program. As part of the settlement, we were handed the
source code so far. Rather than running screaming, our company then
beat that software into submission and went live with it. Then they
handed it to me. If the code was as disaster in the hands of the
original authors, why continue? It's usually faster to start from
scratch than to "fix" badly designed software. That error was a
normal loophole that any software could have had, but I could point to
other ones that shouldn't have been used by any sane programmer.
-- I used to own a mind like a steel trap.
Perhaps if I'd specified a brass one, it
wouldn't have rusted like this.
In article <a00ms6Fml...@mid.individual.net>, go...@gossg.org wrote:
> I stalled a train once. Or rather a program that I'd inherited the
> charge of (which should have been put out of its misery long before
> going live) was miscalculating the weight of TOFC when two short
> trailers were put into one long-trailer space. The program calculated
> the weight of both trailers, but put the second weight over the first
> and left the second trailer weight at zero. Then summed up the
> trailers on each car that our operation were providing to the train
> and handed that to the car marshalling software, which decided how
> many locomotives (and which ones) to use.
> oops.
> We inherited the source code when a software company failed to deliver
> on a promised program. As part of the settlement, we were handed the
> source code so far. Rather than running screaming, our company then
> beat that software into submission and went live with it. Then they
> handed it to me. If the code was as disaster in the hands of the
> original authors, why continue? It's usually faster to start from
> scratch than to "fix" badly designed software. That error was a
> normal loophole that any software could have had, but I could point to
> other ones that shouldn't have been used by any sane programmer.
Just yesterday here in New Zealand a power cut in Wellington caused all
the trains in Auckland to be unusable ... the two cities are 660km apart,
at almost opposite ends of the North Island, with totally separate train
systems, but for some crazy reason the signals in Auckland are controlled
from Wellington. :-\
Just yet another example why New Zealand's pathetic public transport systems.
"Sea Wasp (Ryk E. Spoor)" <seaw...@sgeinc.invalid.com> wrote:
>On 4/27/12 1:43 AM, Derek Lyons wrote:
>> Since locomotives can weight upwards of 400,000 lbs... I'm not sure
>> that 300,000 lb cargo cars are that big an issue.
> One 400,000 pound locomotive may be dragging 100 cars. Yes, it's a BIG >issue when those hundred cars are twice the weight you assumed they >would be.
Assuming those hundred cars are twice the weight you assumed them to
be. Though the max weight has increased dramatically, the average
weight hasn't quite kept pace.
>> Not that there's much track left from 20 or 30 years ago I suspect, railroads
>> routinely spend seriously big bucks upgrading and maintaining their tracks.
> They replace track, mostly, and fill in/maintain the ties and ballast. >Upgrading the design, that's much less common, and much harder to do.
The "design" of tracks hasn't varied notably in most of a century.
What they can and have been doing is using heavier rail, improving the
attachments to the ties, increasing the number of ties per mile,
improving the ballast packing... All of which significantly increase
they weight bearing capacity of the rail, and all largely invisible to
casual inspection.
