Cities Turning to Bicycles



In article <[email protected]>,
"Mark Jones" <[email protected]> wrote:

> "Alan Baker" <[email protected]> wrote in message
> news:[email protected]...
> > In article <[email protected]>,
> > "Mark Jones" <[email protected]> wrote:
> >
> > > "Alan Baker" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > In article <L%[email protected]>,
> > > > "Mark Jones" <[email protected]> wrote:
> > > >
> > > > > "Alan Baker" <[email protected]> wrote in message
> > > > > news:[email protected]...
> > > > > > Oh, please. The simple fact -- and you know it as well as I -- is

> that
> > > > > > access ramp advisory speeds are *ludicrously* low almost *all* the
> > > time.
> > > > > >
> > > > > > They should reflect an appropriate speed for an average vehicle,

> in
> > > good
> > > > > > weather, being properly driven. Instead, they are most frequently

> less
> > > > > > than half that speed.
> > > > >
> > > > > I have never once seen a speed that was set at less than half the
> > > > > speed that a reasonable vehicle could handle.
> > > >
> > > > ********.
> > > >
> > > > Rephrased, you're saying that you never seen a ramp where an average
> > > > vehicle couldn't negotiate it at more than twice the posted speed?
> > > >
> > > > Right.
> > > No. Not without running the risk of sliding off the outside of the

> curve.
> > > My Corvette isn't counted as an average vehicle.

> >
> > You're a liar.

> No I am not. You however are an asshole for calling me a liar.


Yeah, you are.

>
> > >
> > > Given the number of trucks, SUVs and minivans being sold, they may
> > > in fact be close to what would be considered an average vehicle.
> > > Most of the ramps are set at an appropriate speed for my 2004 F-150
> > > 4x4 truck. Taking them at twice the posted speed would be asking for
> > > major trouble.

> >
> > I've driven my brother's Nissan Pathfinder (even before it had its
> > shocks replaced) and it can easily -- easily -- more than double the
> > advisory speeds on most ramps.

> If you are doing that, you should have your license suspended.


For doing something completely safe?

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."
 
"Brent P" <[email protected]> wrote in message
news:fGH8d.193474$D%.78264@attbi_s51...
> In article <[email protected]>, Mark

Jones wrote:
> > "Frank Krygowski" <[email protected]> wrote in message
> > news:[email protected]...
> >> I'm not interested in excuses about how difficult decreasing radii can

be
> >
> > This is bad design. For a PE to say what you just said is ridiculous.
> > To resort to a decreasing radius means that the overall design is

flawed.
> >
> > You should be able to go through a curve without needing to slow
> > down the whole time. This is how you end up with trucks on their
> > side with their cargo spilled all over the place.

>
> I would suggest Frank ride his bicycle through a decreasing radius turn
> that wasn't visable until he was in it such that it forced him to brake
> hard. This would probably be the best lesson as to why this sort of
> design should be avoided. Braking while turning is as ill-advised on a
> bicycle as it is driving. Probably more so.


I really find it hard to understand how he could justify a decreasing
radius turn as being a reasonable thing to build. Just because a
roading program can spit out the stakeout points for a particular
piece of roadway, that doesn't mean that it is a good idea to build it.
 
Mark Jones wrote:

> "Brent P" <[email protected]> wrote in message
> news:fGH8d.193474$D%.78264@attbi_s51...
>
>>In article <[email protected]>, Mark

>
> Jones wrote:
>
>>>"Frank Krygowski" <[email protected]> wrote in message
>>>news:[email protected]...
>>>
>>>>I'm not interested in excuses about how difficult decreasing radii can

>
> be
>
>>>This is bad design. For a PE to say what you just said is ridiculous.
>>>To resort to a decreasing radius means that the overall design is

>
> flawed.
>
>>>You should be able to go through a curve without needing to slow
>>>down the whole time. This is how you end up with trucks on their
>>>side with their cargo spilled all over the place.

>>
>>I would suggest Frank ride his bicycle through a decreasing radius turn
>>that wasn't visable until he was in it such that it forced him to brake
>>hard. This would probably be the best lesson as to why this sort of
>>design should be avoided. Braking while turning is as ill-advised on a
>>bicycle as it is driving. Probably more so.

>
>
> I really find it hard to understand how he could justify a decreasing
> radius turn as being a reasonable thing to build. Just because a
> roading program can spit out the stakeout points for a particular
> piece of roadway, that doesn't mean that it is a good idea to build it.
>


So Frank is an engineer? I thought someone mentioned that he was a
professor? I did a quick search on his name but all I came up with were
a couple bicycling columns that seemed oddly reasonable, given his posts
here.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel
 

>
> I really find it hard to understand how he could justify a decreasing
> radius turn as being a reasonable thing to build. Just because a
> roading program can spit out the stakeout points for a particular
> piece of roadway, that doesn't mean that it is a good idea to build it.
>
>


Such a turn could be designed explicitly for the purpose of slowing
traffic. In that case, a sign can warn of it.

Wayne
 
"Nate Nagel" <[email protected]> wrote
> So Frank is an engineer? I thought someone mentioned that he was a
> professor? I did a quick search on his name but all I came up with were a
> couple bicycling columns that seemed oddly reasonable, given his posts
> here.


Yes, he's a prof at Youngstown, has a BS & MS in Engineering (looks like
the general engineering type of degree), along with a PE license (in Penn,
not OH).
He's on the right in the pic at http://www.eng.ysu.edu/tech/index.htm.
And his vitae is at
http://www.eng.ysu.edu/faculty/faculty.php?USERNAME=frkygowski

You'll probably get a reply soon on your lighting post - he's done some
sort of work for bicycle lighting generators so probably believes he knows
everything about it.

He's *all over* cycling newsgroups and websites.
Google is awesome, but I sometimes have severe concerns about the
WWW and privacy issues.

Floyd
 
In article <HoI8d.19620$n%[email protected]>,
Wayne Pein <[email protected]> wrote:

> >
> > I really find it hard to understand how he could justify a decreasing
> > radius turn as being a reasonable thing to build. Just because a
> > roading program can spit out the stakeout points for a particular
> > piece of roadway, that doesn't mean that it is a good idea to build it.
> >
> >

>
> Such a turn could be designed explicitly for the purpose of slowing
> traffic. In that case, a sign can warn of it.
>
> Wayne


Describe a situation where that would be useful...

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."
 
[email protected] (Brent P) writes:

> In article <[email protected]>, Tim McNamara wrote:
>
>> Indeed, my review of some of the traffic management literature
>> (e.g.,
>> http://ops.fhwa.dot.gov/Travel/traffic/freeway_management_handbook/chapter5.htm)
>> suggests that traffic flow obeys the mathematics governing
>> hydraulic flow, and that there is a maximum throughput in any
>> hydraulic system before turbulence is created. Turbulence in turn
>> creates drag and slows throughput dramatically. You can set the
>> speed limit at the 85th percentile, but that will not "smooth out"
>> traffic flow when there are just too many cars on the road at the
>> same time- which is about 8 hours of every day in major urban
>> areas.

>
> A smooth flow can sustain a higher throughput delaying the onset of
> traffic jams and lessening how long they last.


In an ideal world, sure. But you're dealing with a situation where by
definition 85% of drivers are driving below the posted limit- which
means the faster drivers are tailgating, trying to pass, and creating
turbulence in the traffic flow. This rapidly becomes congestion.
You're also dealing with drivers of radically different driving skills
and driving preferences, so you get people driving 45 mph in the
center lane on a road posted at 80 mph (in your ideal scenario of
using the 85th percentile). Unless you make the minimum speed limit no
more than 5 mph less than the maximum, you're going to continue to
have the same kinds of troubles that you claim higher speed limits
would prevent. Only on level highways with unimpeded sight lines and
miles and miles without turns, on ramps or off ramps would your ideas
work as advertised.

The computer modeling for this makes it very clear and closely mimics
life. A traffic jam during rush hour can literally be caused by one
car hitting the brakes, with other drivers reacting and creating a
chain of events that lead to slow or stopped traffic. The "stopped"
part of the traffic sort of cascades backwards from the original site,
with the driver who caused it normally being blithely unaware of the
havoc he wreaked when he dropped his cell phone. If somebody going 80
mph and needing significantly more stopping distance than someone
going 55 mph rear-ends this joker, you've got a much worse traffic jam
on your hands.

Seems to me you are only looking at the up side which fulfills your
desire to drive faster than you legally can now. There are serious
problems to raising speed limits and with the 85th percentile
proposal.
 
Nate Nagel wrote:

> Frank Krygowski wrote:
>
>> So far, I'm the only one who's produced values. Do you have some?
>> Put them up and we can discuss. If not, you really shouldn't complain
>> about mine.

>
>
> I shouldn't have to, that claim is so ludicrous that it's not even worth
> mentioning. For reference, 300-350 feet is the average length of a city
> block in many areas. Are you really going to tell me, with a straight
> face, that with my high beams on a hazard only a city block away is
> going to be near the edge of visibility? Even in the total absence of
> other light?


First, the site I quoted said 350 to 400 feet. You continually
misrepresent what I say, and always in a way that gives you a slightly
better chance for rebuttal. Keep it honest.

Will your high beams spot a hazard a block away? That depends. I'm
sure you'll say that the 1963 Studebaker was, actually, the pinnacle of
automotive excellence. I'm sure the old car you were in had brilliant
headlights, a _perfectly_ clear windshield, absolutely wonderful brakes,
surprisingly good tires, and a brilliant driver.

But if the hazard were something dark and non-reflective? Say, a deer
bounding across the road? A pedestrian walking toward you at your edge
of the road? A tree branch that had broken off and fallen into the
road? Or especially, any of those that were a block away when an
oncoming car's headlights were _half_ a block away and giving you some
headlight glare?

I think there's a good chance you couldn't see it. I think there's an
even better chance that you could not stop before hitting it, if you
were doing "75+ mph" as you claimed.

You can use different
> standards to "prove" almost anything you want to, but the fact remains
> that high beams that can't provide illumination that is clearly
> acceptable a city block away aren't going to be found on any vehicle *I*
> am willing to drive at night.


It sounds to me like you were willing to ride in one, though!

>
> At 100 ft/s (a hair under 70 MPH) it
> would therefore take a little over 300 feet to stop not counting
> reaction time. Therefore even if near asleep at the wheel, it should be
> possible to stop in under 400 feet.


Interesting. Now you're changing what _you_ said. Why "under 70 mph"
when in your original bragging you claimed "75+ mph"?

Your driving (or, the driving you describe with such approval) was risky
and irresponsible. And as always, you are an apologist for speeding -
despite the problems you've acknowledged with your own driving.

Why does this matter? Because it proves your judgment about traffic
control measures in residential neighborhoods is likely to be distorted
by your desire to speed.



>
>
>>
>> The rest of your post amounts to exactly what I predicted: that boy,
>> that old Studebaker had terrific brakes! And its headlights were
>> perfect or better! And this rural two lane road was guaranteed to be
>> straight, well-paved and deserted. And that if anything _did_ happen,
>> of _course_ it would have been taken care of with perfect aplomb. And
>> as a last tidbit, naturally, you're a better than average driver -
>> just like 85% of the American drivers surveyed.

>
>
> Yes, although I realize you meant that sarcastically, that about sums
> the situation up exactly.
>
>>
>> And as evidence of all that, we have ... well, actually, all we have
>> are your admission of nearly losing it on a freeway, and your personal
>> need for super-accurate speed advisory signs.

>
>
> you are confusing "need" and "want." There are very few situations
> where one actually "needs" advisory signs at all.


Someone who has barely stayed on the freeway seems to _need_ such a
sign! You've gone on and on about how it was impossible for you to
judge that curve!


--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]
 
In article <HoI8d.19620$n%[email protected]>, Wayne Pein wrote:

<decreasing radius turns>

> Such a turn could be designed explicitly for the purpose of slowing
> traffic. In that case, a sign can warn of it.


If a curve is desired to slow traffic, then take the tightest radius
value and use that for a constant radius turn. It will slow traffic just
as good if not better and not have the drawbacks.
 
Alan Baker wrote:

>
> What prevents the driver from having driven the road before and
> *knowing* there are no hills curves or blindspots?


Ask Nate, Alan. Ask him how many minutes before he had gone down the
road to check it for hills, curves, blind spots - and tree branches,
pedestrians, drivers backing out of driveways, and other road hazards.

Again: people who defend night driving at 75+ mph on rural two-lane
roads lack the judgement to comment on mitigating neighborhood speeding.


--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]
 
Nate Nagel <[email protected]> writes:

> Tim McNamara wrote:
>
>> Frank Krygowski <[email protected]> writes:
>>
>>>Brent P wrote:
>>>
>>>>In article <[email protected]>, Frank Krygowski wrote:
>>>>
>>>>>If you want to delve deeply into the psychology and physics, we
>>>>>can do it. But self-proclaimed "skilled drivers" are seldom as
>>>>>fast in reaction as they pretend. Unanticipated events take
>>>>>quite a while to process.
>>>
>>>>If the speed kills stuff you proclaim is correct, chicago area
>>>>expressways would be coated in blood 24 hours a day, 7 days a
>>>>week. The dan ryan expressway alone shows reaction times are far
>>>>better than what you are saying. But that's neither here nor
>>>>there. smoothing out the flow greatly reduces the number of events
>>>>to react to. 85th percentile speed limits are key to smoothing the
>>>>traffic flow.

>
>> Would that it were that simple, but it isn't. Competent road
>> design- something that is distinctly lacking on most roads- is one
>> of the keys. Development of higher standards for obtaining a
>> license to drive would be another. The absolute speed of driving
>> isn't as much issue as the bottlenecks caused by road design
>> problems and the interaction between vehicles. Indeed, my review
>> of some of the traffic management literature (e.g.,
>> http://ops.fhwa.dot.gov/Travel/traffic/freeway_management_handbook/chapter5.htm)
>> suggests that traffic flow obeys the mathematics governing
>> hydraulic flow, and that there is a maximum throughput in any
>> hydraulic system before turbulence is created. Turbulence in turn
>> creates drag and slows throughput dramatically. You can set the
>> speed limit at the 85th percentile, but that will not "smooth out"
>> traffic flow when there are just too many cars on the road at the
>> same time- which is about 8 hours of every day in major urban
>> areas.

>
> It will smooth out the flow a little by narrowing the distribution
> of speeds, but you're right, that's a minor effect. It will,
> however, increase the capacity of the road by allowing people to
> spend less time on it (ASSuming, of course, that it's grossly
> underposted to the point where speeds are artificially depressed
> now.)


But will it narrow the distribution of speeds? Will the people who
drive no faster than 50 or 55 mph now suddenly decide they'll happily
drive at 75 or 80 just because the speed limit got raised? By
definition, 85% of people would drive below the posted limit which, it
seems to me, would increase the distribution of speeds rather than
reduce it. This in turn would increase traffic problems due to
interactions between cars moving at significantly different speeds.

In an ideal world where everyone has a similar level of driving skill
competence, vehicles capable of similar speeds, and perhaps also
limited on- and off ramps, segregation of large/slower truck traffic
and automobile traffic, etc., you might make this work. But I see
just tons of worse problems from speed limits being posted too high
for the majority of drivers to deal with effectively.
 
Mark Jones wrote:

> "Frank Krygowski" <[email protected]> wrote in message
> news:[email protected]...
>
>>I'm not interested in excuses about how difficult decreasing radii can be..

>
>
> This is bad design. For a PE to say what you just said is ridiculous.
> To resort to a decreasing radius means that the overall design is flawed.
>
> You should be able to go through a curve without needing to slow
> down the whole time. This is how you end up with trucks on their
> side with their cargo spilled all over the place.


Are you saying you couldn't handle a decreasing radius curve? Do _you_,
personally, need to have only _increasing_ radius curves to be able to
successfully stay on the road?

How about on a two lane road? Do you want to see only increasing curve
radii when you're heading, say, east?

And Mark - what sort of engineering tricks do you want used when you
turn around and drive west?


--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]
 
Alan Baker wrote:

> In article <[email protected]>,
> Frank Krygowski <[email protected]> wrote:
>
>
>>
>>I was merely responding to what you wrote. If the "you can see for
>>miles" statement was false, you shouldn't have posted it.

>
>
> My statement wasn't false.
>


Well, explain. I'm having trouble visualizing a dark nighttime road
that you can see down "for miles." Especially in the original context -
a rural road in Virginia.

Have you been to Virgina? It's not like, say, Nevada or Montana. There
are hills, contours and curves aplenty.

Perhaps you should start with how you see miles in the dark in Nevada.
Then tell how it works in Virginia.

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]
 
Frank Krygowski wrote:

> Nate Nagel wrote:
>
>> Frank Krygowski wrote:
>>
>>> So far, I'm the only one who's produced values. Do you have some?
>>> Put them up and we can discuss. If not, you really shouldn't
>>> complain about mine.

>>
>>
>>
>> I shouldn't have to, that claim is so ludicrous that it's not even
>> worth mentioning. For reference, 300-350 feet is the average length
>> of a city block in many areas. Are you really going to tell me, with
>> a straight face, that with my high beams on a hazard only a city block
>> away is going to be near the edge of visibility? Even in the total
>> absence of other light?

>
>
> First, the site I quoted said 350 to 400 feet. You continually
> misrepresent what I say, and always in a way that gives you a slightly
> better chance for rebuttal. Keep it honest.


I was putting it in real-world terms. "City block" has a lot more
meaning to most people than "350 feet." Yes, I realize that 350 feet is
less than 400 feet. That's why I said "near the edge of visibility"
rather than "at the edge of visibility."

>
> Will your high beams spot a hazard a block away? That depends. I'm
> sure you'll say that the 1963 Studebaker was, actually, the pinnacle of
> automotive excellence. I'm sure the old car you were in had brilliant
> headlights,


As stated before, they were high-output halogen sealed beams. Not the
absolute best lighting available, but decent. I was actually impressed
with their performance, certainly better than the lights installed on
some brand new cars, at least subjectively.

> a _perfectly_ clear windshield,



yes, actually the windshield was brand new. I helped to replace it. I
believe the first time wipers ever dragged across it was on the trip down.

> absolutely wonderful brakes,


They don't have to be "wonderful," just as good as the tires.

> surprisingly good tires,


Brand new repro 6.70-15s. Not the best tires by a long shot, but
adequate and in good condition.

> and a brilliant driver.


You don't have to be brilliant to drive 75 MPH safely on a straight,
deserted road. Merely reasonably skilled and aware.

>
> But if the hazard were something dark and non-reflective? Say, a deer
> bounding across the road?


Easy to spot.

> A pedestrian walking toward you at your edge
> of the road?


in a fenced-off military installation?

> A tree branch that had broken off and fallen into the
> road?


Also easy to spot.

> Or especially, any of those that were a block away when an
> oncoming car's headlights were _half_ a block away and giving you some
> headlight glare?


Oncoming cars we saw maybe one every 20 minutes or so.

>
> I think there's a good chance you couldn't see it. I think there's an
> even better chance that you could not stop before hitting it, if you
> were doing "75+ mph" as you claimed.
>
> You can use different
>
>> standards to "prove" almost anything you want to, but the fact remains
>> that high beams that can't provide illumination that is clearly
>> acceptable a city block away aren't going to be found on any vehicle
>> *I* am willing to drive at night.

>
>
> It sounds to me like you were willing to ride in one, though!


Prove it. I've already given you all the info you should need, they
were off the shelf high output H6014 sealed beams (probably sylvania but
I don't remember) and the alternator was putting out appx. 14.7V.
Calculate a rough estimate of voltage drop from the alt. to the
headlights, find the light output at that voltage and prove to me that I
couldn't see an obstacle 400 feet away. You made the claim, you back it up.

>
>>
>> At 100 ft/s (a hair under 70 MPH) it would therefore take a little
>> over 300 feet to stop not counting reaction time. Therefore even if
>> near asleep at the wheel, it should be possible to stop in under 400
>> feet.

>
>
> Interesting. Now you're changing what _you_ said. Why "under 70 mph"
> when in your original bragging you claimed "75+ mph"?


Because I didn't feel like looking for a calculator, that's why. 70 MPH
is just a tick over 100 ft/sec which is a really handy number for
cocktail napkin calculations. If it really bothers you, do the math
yourself and then prove to me that I couldn't have seen an obstacle at
whatever distance it takes to stop from exactly 75 MPH or whatever value
makes you happy.

Keep in mind, of course, that since time immemorial speedometers have
been pessimistic, for liability reasons. So an indicated "75+" is
actually more like 72 or 73 if you want to be really nitpicky about it.

>
> Your driving (or, the driving you describe with such approval) was risky
> and irresponsible. And as always, you are an apologist for speeding -
> despite the problems you've acknowledged with your own driving.


I'm not an apologist for anything. I neither approve nor disapprove of
my friend's driving, I didn't actually think it was that remarkable.
It's an ordinary, everyday occurrance and the only thing out of the
ordinary was the fact that we were doing it in a car quite a bit more
interesting and involving than your average econobox. However, it's a
memorable incident to me just because of the sharp contrast of fighting
insane traffic in the DC area. FWIW, and I realize you are going to
manage to spin this somehow to try to make me look bad, but on the
shifts that I was driving, I probably averaged 5-10 MPH slower, simply
because it wasn't my car and I wanted to make extra certain that nothing
bad happened (although it wasn't fear of hitting something that slowed
me down; it was more concern for the car's mechanicals - the tachometer
wasn't working, but I'm sure that we were turning pretty close to 4000
RPM for decent periods of time with a 3.73:1 rear end. It *should* have
been in top condition, but still, it's Someone Else's Car...)

>
> Why does this matter? Because it proves your judgment about traffic
> control measures in residential neighborhoods is likely to be distorted
> by your desire to speed.
>


My "desire to speed?" If you consider "speeding" to be simply exceeding
a number on a sign, then yes, I suppose so, I generally regard most
speed limits outside of residential areas as handy guides to how fast I
should travel when a police officer is visible. If you consider it to
be exceeding a safe speed for conditions, absolutely not. I have no
more desire to damage myself, my property, anyone else, or anyone else's
property than you do. (I am probably *more* concerned about such than
most people, judging by the average driving "skill" level observed
locally.) Hence my concern when *some* speed limits correctly reflect a
safe upper bound speed for normal vehicles but *most* do not.

>
>
>>
>>
>>>
>>> The rest of your post amounts to exactly what I predicted: that boy,
>>> that old Studebaker had terrific brakes! And its headlights were
>>> perfect or better! And this rural two lane road was guaranteed to be
>>> straight, well-paved and deserted. And that if anything _did_
>>> happen, of _course_ it would have been taken care of with perfect
>>> aplomb. And as a last tidbit, naturally, you're a better than
>>> average driver - just like 85% of the American drivers surveyed.

>>
>>
>>
>> Yes, although I realize you meant that sarcastically, that about sums
>> the situation up exactly.
>>
>>>
>>> And as evidence of all that, we have ... well, actually, all we have
>>> are your admission of nearly losing it on a freeway, and your
>>> personal need for super-accurate speed advisory signs.

>>
>>
>>
>> you are confusing "need" and "want." There are very few situations
>> where one actually "needs" advisory signs at all.

>
>
> Someone who has barely stayed on the freeway seems to _need_ such a
> sign! You've gone on and on about how it was impossible for you to
> judge that curve!
>
>


The sign was there, I just disregarded it as experience had taught me
was normally safe to do. That's the whole reason that speed limits
should be raised whenever it's safe to do so.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel
 
Frank Krygowski wrote:

> Alan Baker wrote:
>
>>
>> What prevents the driver from having driven the road before and
>> *knowing* there are no hills curves or blindspots?

>
>
> Ask Nate, Alan. Ask him how many minutes before he had gone down the
> road to check it for hills, curves, blind spots - and tree branches,
> pedestrians, drivers backing out of driveways, and other road hazards.


Approximately five days before. But, as I've repeatedly explained, we
were driving through a military base. Not much danger of pedestrians or
driveways, and I don't think any hills, curves, or blind spots are going
to appear within a week.

>
> Again: people who defend night driving at 75+ mph on rural two-lane
> roads lack the judgement to comment on mitigating neighborhood speeding.


"defend?" There's nothing to defend. It's a common, everyday occurrance.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel
 
Frank Krygowski wrote:

> Mark Jones wrote:
>
>> "Frank Krygowski" <[email protected]> wrote in message
>> news:[email protected]...
>>
>>> I'm not interested in excuses about how difficult decreasing radii
>>> can be..

>>
>>
>>
>> This is bad design. For a PE to say what you just said is ridiculous.
>> To resort to a decreasing radius means that the overall design is flawed.
>>
>> You should be able to go through a curve without needing to slow
>> down the whole time. This is how you end up with trucks on their
>> side with their cargo spilled all over the place.

>
>
> Are you saying you couldn't handle a decreasing radius curve? Do _you_,
> personally, need to have only _increasing_ radius curves to be able to
> successfully stay on the road?
>
> How about on a two lane road? Do you want to see only increasing curve
> radii when you're heading, say, east?
>
> And Mark - what sort of engineering tricks do you want used when you
> turn around and drive west?
>


Blind curves should *never* be decreasing radius. Never. If a road has
traffic in two directions, a blind curve should be, by necessity,
constant radius.

This isn't that difficult a concept to grasp; I don't know why you're
having such trouble with it.

nate

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"Nate Nagel" <[email protected]> wrote in message
news:[email protected]...
> So Frank is an engineer? I thought someone mentioned that he was a
> professor? I did a quick search on his name but all I came up with were
> a couple bicycling columns that seemed oddly reasonable, given his posts
> here.


According to the what I could find out, he is a Professor with a
Professional Engineer(P.E.) certification. I sure looks like he
teaches in the Mechanical Engineering Technology program.

Kind of interesting what he teaches, considering that I have
a B.S. in Electronics Engineering Technology and built a
large scale automated test system that would be related
to his interests as listed on the following page.

http://www.eng.ysu.edu/tech/MET.htm

Scroll to the bottom of the page.
 
Frank Krygowski wrote:

> Alan Baker wrote:
>
>> In article <[email protected]>,
>> Frank Krygowski <[email protected]> wrote:
>>
>>
>>>
>>> I was merely responding to what you wrote. If the "you can see for
>>> miles" statement was false, you shouldn't have posted it.

>>
>>
>>
>> My statement wasn't false.
>>

>
> Well, explain. I'm having trouble visualizing a dark nighttime road
> that you can see down "for miles." Especially in the original context -
> a rural road in Virginia.
>
> Have you been to Virgina? It's not like, say, Nevada or Montana. There
> are hills, contours and curves aplenty.


Perhaps in western Virginia. Not so much in the eastern portion of the
state. Any curves, hills, etc. are of the variety that are so mild as
to pose no problem at all at any reasonable vehicular traffic speed.

>
> Perhaps you should start with how you see miles in the dark in Nevada.
> Then tell how it works in Virginia.
>


It's really easy, you just flip on the high beams.

A nice bonus of the flat terrain is that the moonlight actually helps
you, as the only shadows are from the trees.

nate

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"Wayne Pein" <[email protected]> wrote in message
news:HoI8d.19620$n%[email protected]...
>
> >
> > I really find it hard to understand how he could justify a decreasing
> > radius turn as being a reasonable thing to build. Just because a
> > roading program can spit out the stakeout points for a particular
> > piece of roadway, that doesn't mean that it is a good idea to build it.
> >
> >

>
> Such a turn could be designed explicitly for the purpose of slowing
> traffic. In that case, a sign can warn of it.


The only one that I ever remember encountering did not have
any warnings posted and the posted speed was O.K. for the
entry, but not for the rest of the curve. I saw what was happening
right away and got on the brakes or it would have gotten real
interesting.

I do not like decreasing radius curves as they can be very dangerous.
 

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