Register a SA Forums Account here!
JOINING THE SA FORUMS WILL REMOVE THIS BIG AD, THE ANNOYING UNDERLINED ADS, AND STUPID INTERSTITIAL ADS!!!

You can: log in, read the tech support FAQ, or request your lost password. This dumb message (and those ads) will appear on every screen until you register! Get rid of this crap by registering your own SA Forums Account and joining roughly 150,000 Goons, for the one-time price of $9.95! We charge money because it costs us money per month for bills, and since we don't believe in showing ads to our users, we try to make the money back through forum registrations.
 
  • Post
  • Reply
Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...

Baronjutter posted:

What's the source on this and why are none of the axis labelled?

Jasper Tin Neck posted:

I drew a quick schematic graph of two variables assuming similar levels of service, but there are many more (such as length of the trip, speed, convenience etc.)

Adbot
ADBOT LOVES YOU

Jasper Tin Neck
Nov 14, 2008


"Scientifically proven, rich and creamy."

Volmarias posted:

Alright, pretty reasonable explanations all. I understand the concept of public utility, I guess I'm just surprised that some lines aren't run more profitably (i.e. very large vehicles on mostly empty runs, etc).
Have another one of my graphs!*

Most of you probably already know that transportation demand tends to be pretty cyclical with peaks during the morning and evening rush hours when people go to and come from work. What might come as a surprise is that about 40% of all traffic is leisure-related. The convenience of a given mode of transportation during our free time is usually what determines what mode of transport we favour. If the trains only ran during rush hour, most people with a social life would say: "Screw it, I'm getting a car/motorcycle/scooter!" And when people have made such an investment, they tend to use their vehicle when going to work too. Hence it often pays off to run public transit seemingly in excess of demand during slow hours.

In addition to this, the reason why cities tend to run a seemingly excessive train fleet during slow hours is that taking trains or individual carriages offline is a fairly laborious process which requires exiting the mainline and entering a depot. Since labour costs are a fairly large part of the operating costs of any western transportation system, you want to avoid unnecessary entry/exit operations, especially during the day when slow hours only last some 5-6 h anyway. Running a constant number of vehicle during the day also makes personnel rostering much easier.
*(for educational purposes only)

Chaos Motor posted:

You can't discount the independence aspect of private transportation. With public transportation, you don't have any control over the vehicle, schedule, or destination. With private transportation, you have some measure of control over what you ride in, where you go, and when. That is probably the biggest issue in most cities - people want to know that they have control over their transportation. I, for one, would much rather spend more to have a car and leave now than wait for some dirty old bus full of weirdos that's always late and requires three transfers and still only gets me two miles from my destination.

If we want widespread public transportation to be acceptable to the general public, we have to be able to arrive within a quarter or half mile of our destination, within five minutes of desiring to leave, with minimal transfers. In a city like Kansas City, that's a massive requirement.
This is perfectly true. It's even been shown that (contrary to what people will say if asked) for the average full-time employed person, the cost of tickets is a fairly insignificant factor in deciding whether to use public transport or not. Safety, comfort, reliability, availability of route and schedule information, shelter facilities and many more have a far larger impact on transportation decisions than fare prices.

Unfortunately some cities just aren't built to operate a good mass transit system because of the way they are designed, no matter how nice the facilities. Usually bus stops are assumed to have a catchment radius of 300m, while train stations have a catchment radius of 600-1000m. If there aren't enough homes, businesses or entertainment venues within that radius to provide an adequate ridership, it doesn't make sense economically to operate mass transit, no matter how bad traffic gets. Park-and-ride schemes might offer a solution to this problem, but the evidence of their efficiency is still inconclusive.

Jasper Tin Neck fucked around with this message at 23:35 on Nov 2, 2011

Buffer
May 6, 2007
I sometimes turn down sex and blowjobs from my girlfriend because I'm too busy posting in D&D. PS: She used my credit card to pay for this.
Have any New England traffic engineers broken under the stress of insane demands from the public, ancient designs/infrastructure running at exponential capacity, and turned evil?

I ask because of this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(There are a ton of lights there, most have about 15 seconds of green - it's a rotary from hell)
and this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(there are two lights there, one recent for a new parking lot. They left the old one on for some reason, on different timing than the new one so traffic is disrupted, and both are off-sync from the one up the road - this causes traffic to back up past the rotary to the previous one - it takes until around 8pm for everything to clear).
and this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(the highway goes from 3 lanes to 2 for the bridge over the rotary right before traffic merges from 60, it expands back out to 3 lanes much later - this little gem probably costs everyone going northbound 45 minutes stuck in traffic at rush hour)

Buffer fucked around with this message at 00:57 on Nov 3, 2011

kefkafloyd
Jun 8, 2006

What really knocked me out
Was her cheap sunglasses

Buffer posted:

Have any New England traffic engineers broken under the stress of insane demands from the public, ancient designs/infrastructure running at exponential capacity, and turned evil?

I ask because of this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(There are a ton of lights there, most have about 15 seconds of green - it's a rotary from hell)
and this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(there are two lights there, one recent for a new parking lot. They left the old one on for some reason, on different timing than the new one so traffic is disrupted, and both are off-sync from the one up the road - this causes traffic to back up past the rotary to the previous one - it takes until around 8pm for everything to clear).
and this:
http://maps.google.com/maps?q=1A+an...+02151&t=h&z=18
(the highway goes from 3 lanes to 2 for the bridge over the rotary right before traffic merges from 60, it expands back out to 3 lanes much later - this little gem probably costs everyone going northbound 45 minutes stuck in traffic at rush hour)

On the last one, it goes down to 3 lanes because one of the lanes was supposed to be exit-only to those ghost ramps, which were to be I-95. The other rotaries are just years and years of glomming-on.

Route 1 is the only road I ever drive on where I feel like I'm actively taking my life into my own hands.

Also, we drove back from New York City on Sunday night. The 50-ish miles of East Hartford to Oxford were in complete darkness, the only other lights from cars. It was even eerier than the blackout we had back in... 2002?

Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...

Jasper Tin Neck posted:

Have another one of my graphs!*

Most of you probably already know that transportation demand tends to be pretty cyclical with peaks during the morning and evening rush hours when people go to and come from work. What might come as a surprise is that about 40% of all traffic is leisure-related. The convenience of a given mode of transportation during our free time is usually what determines what mode of transport we favour. If the trains only ran during rush hour, most people with a social life would say: "Screw it, I'm getting a car/motorcycle/scooter!" And when people have made such an investment, they tend to use their vehicle when going to work too. Hence it often pays off to run public transit seemingly in excess of demand during slow hours.

In addition to this, the reason why cities tend to run a seemingly excessive train fleet during slow hours is that taking trains or individual carriages offline is a fairly laborious process which requires exiting the mainline and entering a depot. Since labour costs are a fairly large part of the operating costs of any western transportation system, you want to avoid unnecessary entry/exit operations, especially during the day when slow hours only last some 5-6 h anyway. Running a constant number of vehicle during the day also makes personnel rostering much easier.
*(for educational purposes only)

This is perfectly true. It's even been shown that (contrary to what people will say if asked) for the average full-time employed person, the cost of tickets is a fairly insignificant factor in deciding whether to use public transport or not. Safety, comfort, reliability, availability of route and schedule information, shelter facilities and many more have a far larger impact on transportation decisions than fare prices.

Unfortunately some cities just aren't built to operate a good mass transit system because of the way they are designed, no matter how nice the facilities. Usually bus stops are assumed to have a catchment radius of 300m, while train stations have a catchment radius of 600-1000m. If there aren't enough homes, businesses or entertainment venues within that radius to provide an adequate ridership, it doesn't make sense economically to operate mass transit, no matter how bad traffic gets. Park-and-ride schemes might offer a solution to this problem, but the evidence of their efficiency is still inconclusive.

Ok, that's actually a pretty well written explanation. I had never realized that taking transit offline might be more expensive than just letting it roll; I figured that fuel costs would be one of the larger costs.

Awesome responses, thanks :)

Cichlidae
Aug 12, 2005

ME LOVE
MAKE RED LIGHT


Dr. Infant, MD

kefkafloyd posted:

Also, we drove back from New York City on Sunday night. The 50-ish miles of East Hartford to Oxford were in complete darkness, the only other lights from cars. It was even eerier than the blackout we had back in... 2002?

It was in 2003. http://en.wikipedia.org/wiki/Northeast_blackout_of_2003

I was in Cape Cod on vacation, and didn't even find out about the blackout until I got back home.

GWBBQ
Jan 2, 2005


Is there any reason other than a fatal accident that the DOT would shut off the cameras on 95?

Cichlidae
Aug 12, 2005

ME LOVE
MAKE RED LIGHT


Dr. Infant, MD

GWBBQ posted:

Is there any reason other than a fatal accident that the DOT would shut off the cameras on 95?

Doesn't need to be fatal. Any kind of accident can trigger a blackout. Also, keep in mind that cameras in the field have downtime around 1%; at any given time, a few of them aren't going to be working. When you get a whole bunch of them down in a corridor, though, it's most likely a problem with the operations center or the website host. We can tolerate a camera or two in a row broken, but 3 or more, and you're basically blind in that area.

FISHMANPET
Mar 3, 2007

Sweet 'N Sour
Can't
Melt
Steel Beams

Jasper Tin Neck posted:

Have another one of my graphs!*

Most of you probably already know that transportation demand tends to be pretty cyclical with peaks during the morning and evening rush hours when people go to and come from work. What might come as a surprise is that about 40% of all traffic is leisure-related. The convenience of a given mode of transportation during our free time is usually what determines what mode of transport we favour. If the trains only ran during rush hour, most people with a social life would say: "Screw it, I'm getting a car/motorcycle/scooter!" And when people have made such an investment, they tend to use their vehicle when going to work too. Hence it often pays off to run public transit seemingly in excess of demand during slow hours.

In addition to this, the reason why cities tend to run a seemingly excessive train fleet during slow hours is that taking trains or individual carriages offline is a fairly laborious process which requires exiting the mainline and entering a depot. Since labour costs are a fairly large part of the operating costs of any western transportation system, you want to avoid unnecessary entry/exit operations, especially during the day when slow hours only last some 5-6 h anyway. Running a constant number of vehicle during the day also makes personnel rostering much easier.
*(for educational purposes only)

This is perfectly true. It's even been shown that (contrary to what people will say if asked) for the average full-time employed person, the cost of tickets is a fairly insignificant factor in deciding whether to use public transport or not. Safety, comfort, reliability, availability of route and schedule information, shelter facilities and many more have a far larger impact on transportation decisions than fare prices.

Unfortunately some cities just aren't built to operate a good mass transit system because of the way they are designed, no matter how nice the facilities. Usually bus stops are assumed to have a catchment radius of 300m, while train stations have a catchment radius of 600-1000m. If there aren't enough homes, businesses or entertainment venues within that radius to provide an adequate ridership, it doesn't make sense economically to operate mass transit, no matter how bad traffic gets. Park-and-ride schemes might offer a solution to this problem, but the evidence of their efficiency is still inconclusive.

In the long term, this stuff effects where people live too, which makes it hard to change commuting habits. And there's all sorts of misunderstandings the brain makes when it evaluates tradeoffs in a situation like this (moving farther away from work to get a bigger house, etc). Mainly, the brain tends to overestimate the impact of the positives (a spare bedroom!) and underestimate the impact of the negatives (spending 45 minutes more in the car each day).

There's also a "problem" when comparing trip times. Generally transit trips take longer than driving trips, even in places like NYC. So having never ridden a bus, you can look at the numbers and say "I'm losing X minutes a day riding the bus!" and then you sit in traffic for an hour a day, whereas the guy who rides the bus for an hour and a half a day has an hour a half to read, or close his eyes, or maybe even get some work done.

It basically takes a completely different mindset to start using transit. I think part of it requires giving up a little bit of your Independence in return for quite a bit of extra time. The 5 minutes I stand at a bus stop waiting for a bus isn't wasted time, it's when I catch up on my news reading and such. A smart phone really changes the whole game in this respect.

IOwnCalculus
Apr 2, 2003





Counterpoint: Smartphones or not, the guy spending 45 minutes each way driving to work and back can spend a lot more time with his family at home than the guy spending 1.5 hours each way who uses a combination of bus and bicycle.

If only there was an express bus that stopped somewhere further east than Central Ave :smith:

Wolfy
Jul 13, 2009

IOwnCalculus posted:

Counterpoint: Smartphones or not, the guy spending 45 minutes each way driving to work and back can spend a lot more time with his family at home than the guy spending 1.5 hours each way who uses a combination of bus and bicycle.

If only there was an express bus that stopped somewhere further east than Central Ave :smith:
Is an hour and a half really "a lot" more time?

Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...

Wolfy posted:

Is an hour and a half really "a lot" more time?

Yes, it is. 16 usable hours in the day, 8-9 at work. that leaves 8-7 hours for yourself/family. 1 hour will probably be spent doing your morning toilette, leaving 7-6. 1.5 hours out of 7 is 21% of your free day, and 25% out of 6.

Wolfy
Jul 13, 2009

Volmarias posted:

Yes, it is. 16 usable hours in the day, 8-9 at work. that leaves 8-7 hours for yourself/family. 1 hour will probably be spent doing your morning toilette, leaving 7-6. 1.5 hours out of 7 is 21% of your free day, and 25% out of 6.
But consider that commuting via car is rather stressful and that you may be more efficient in that 6-7 hours and the time you spend with your family may be of higher quality. I also know that after driving home from LA after a long day, I spend a good 30 minutes to an hour doing jack poo poo because it's an awfully draining commute with all the traffic. YMMV, though.

hoboslayer
Feb 19, 2003
but but but... i swear i guessed the right number!

Wolfy posted:

But consider that commuting via car is rather stressful and that you may be more efficient in that 6-7 hours and the time you spend with your family may be of higher quality. I also know that after driving home from LA after a long day, I spend a good 30 minutes to an hour doing jack poo poo because it's an awfully draining commute with all the traffic. YMMV, though.

Not everyone finds their commute stressful. Also, a bus/train situation can sometimes be much less comfortable than a car. An uncomfortable commute after a lovely day can really sour someone.

KozmoNaut
Apr 23, 2008

Happiness is a warm
Turbo Plasma Rifle


hoboslayer posted:

Not everyone finds their commute stressful. Also, a bus/train situation can sometimes be much less comfortable than a car. An uncomfortable commute after a lovely day can really sour someone.

Getting stuck in erratic stop-and-go traffic can really sour you, too.

Jasper Tin Neck
Nov 14, 2008


"Scientifically proven, rich and creamy."

FISHMANPET posted:

In the long term, this stuff effects where people live too, which makes it hard to change commuting habits. And there's all sorts of misunderstandings the brain makes when it evaluates tradeoffs in a situation like this (moving farther away from work to get a bigger house, etc). Mainly, the brain tends to overestimate the impact of the positives (a spare bedroom!) and underestimate the impact of the negatives (spending 45 minutes more in the car each day).
It could also very well be that you're not cognizant of the trade-off when you're making the decision. Many people never bother to run the numbers on how much time and money they have to use of transportation after moving, but the realtor is right there to make sure you know how awesome it would be to have an extra bedroom and a big back yard.

KozmoNaut posted:

Getting stuck in erratic stop-and-go traffic can really sour you, too.
Yes, but at least you're sitting in an air-conditioned car with a seat adjusted to your dimensions. You don't even have to put up with crazies trying to push Chick tracts on you.

In the end, debating which method of commuting sucks worse never really gets anywhere because it's so dependent on location, time and personal preference. What a traffic planner has to do is to try to find a compromise that suits most people and deal with the fact that you can never make everyone happy.

FISHMANPET
Mar 3, 2007

Sweet 'N Sour
Can't
Melt
Steel Beams

KozmoNaut posted:

Getting stuck in erratic stop-and-go traffic can really sour you, too.

There have been studies done that say the worst part about traffic like that is the unpredictability. If it was the same exact thing every day it would be fine, but when every day is a new and horrible surprise, that's what really grates on you.

Jasper Tin Neck
Nov 14, 2008


"Scientifically proven, rich and creamy."

FISHMANPET posted:

There have been studies done that say the worst part about traffic like that is the unpredictability. If it was the same exact thing every day it would be fine, but when every day is a new and horrible surprise, that's what really grates on you.
The worst part is that for the time being, most of the models used to predict traffic behaviour don't model reliability at all. It could be a major contributor to the so-called rail factor, i.e. the fact that given similar travel times, people tend to prefer rail-borne modes of public transport over road-borne.

Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...

Jasper Tin Neck posted:

The worst part is that for the time being, most of the models used to predict traffic behaviour don't model reliability at all. It could be a major contributor to the so-called rail factor, i.e. the fact that given similar travel times, people tend to prefer rail-borne modes of public transport over road-borne.

Another major contributor could be the perceptions of who rides the bus vs who rides the train. It turns into a self fulfilling prophecy.

Jasper Tin Neck
Nov 14, 2008


"Scientifically proven, rich and creamy."

Volmarias posted:

Another major contributor could be the perceptions of who rides the bus vs who rides the train. It turns into a self fulfilling prophecy.
Add to that the fact that train stations tend to have better shelters and facilities than bus stops and that air conditioning is more reliable on trains and you already have a pretty good list of reasons why people rather ride the train. But like I said, these are pretty difficult to model.

Mandalay
Mar 16, 2007

WoW Forums Refugee

Volmarias posted:

Another major contributor could be the perceptions of who rides the bus vs who rides the train. It turns into a self fulfilling prophecy.

An interesting way to see this factor in play is to see who rides the bus in Sydney, Rome, etc as opposed to Los Angeles.

FISHMANPET
Mar 3, 2007

Sweet 'N Sour
Can't
Melt
Steel Beams

Jasper Tin Neck posted:

Add to that the fact that train stations tend to have better shelters and facilities than bus stops and that air conditioning is more reliable on trains and you already have a pretty good list of reasons why people rather ride the train. But like I said, these are pretty difficult to model.

When it comes down to it, the rail vs bus debate comes down to right of way. When we think of rail, we're either thinking of a subway/el or light rail. Subway/el is heavy rail, or exclusive right of way and there isn't a rubber tire method that competes with it (with the exception of a rubber tired metro in Paris). When it comes to light rail, you're actually talking about separate right of way. The route has a dedicated route that it doesn't share with general traffic, though it may intersect traffic at grade crossings. Here you can compare BRT vs LRT, and a lot of the "rail" advantages can be put into a BRT system (the main exceptions being the smoothness and fuel efficiency of steel wheels vs rubber wheels). When we talk about buses, we're talking about shared right of way, which in rail terms you could compare to a trolley or street car.

Grand Fromage
Jan 30, 2006

L-l-look at you bar-bartender, a-a pa-pathetic creature of meat and bone, un-underestimating my l-l-liver's ability to metab-meTABolize t-toxins. How can you p-poison a perfect, immortal alcohOLIC?


Light rail also has the advantage that trains are awesome and buses suck.

I come from a midwest US town and now live in an entire country (Korea) where there's no reason to own a car. The mass transit is great everywhere, even in my city, which is the largest in the country without a subway. Supposedly we're getting a tram line. We also have the highest rate of car ownership in the country, 37%. :lol:

It's liberating not having to deal with private transport. New York's transit is better but a good bus system does the job.

Hong Kong's mass transit is amazing too, though it still has the giant problem of closing at night.

Koesj
Aug 3, 2003
I'm in a country with decent PT and lots of people using bikes but this still hasn't put a dent in traffic growth, au contraire:


Historical traffic volumes on freeways in the western Netherlands (Randstad)




I've been adding more and more stuff to my database to try and explain this growth (which was substantially larger than in Belgium and the Rhein-Ruhr) but it's all pretty intricate

Baronjutter
Dec 31, 2007

"Tiny Trains"

I've heard that traffic is not like a liquid that just needs the right width of a channel to flow through, but like a gas, that will simply fill all available space.

Maybe the OP or others can correct me if i'm being overly simplistic, but basically if you build a road or highway, it will fill up to a barely tolerable level of traffic within a few years. Double the highway? A few years you get double the traffic, it never solves anything. All that happens is that it encourages more people to drive, and allows more sprawl.

Wasn't there some case in NYC where they shut down some fairly important and very clogged street and all the traffic "experts" freaked out that it would clog all the nearby streets while a few locals say "nah, they'll just choose another way to get around" and not only did the neighbouring streets not experience the "over-flow" but overall traffic in the area improved?

If you build it, they will drive on it. If you don't built it, they'll walk or take the train. Cars are a pretty comfortable way of getting around, and if you make it too easy people are quickly seduced. Make driving not so pleasant, allow terrible traffic to act as a moderating factor, and people will get around another way. The key though, and what's lacking in north america, is that the "other way" is generally horrible or non-existing.

I bet you anything those dutch maps increase in traffic do not correspond to increases in population, but rather increases in highway capacity.

Chaos Motor
Aug 29, 2003

by vyelkin
Yeah that is a basic networking issue, if you have a network with a set flow and add a link between them, the average time of traversal actually increases.

http://www.davros.org/science/roadparadox.html

kapinga
Oct 12, 2005

I am not a number

Baronjutter posted:

I've heard that traffic is not like a liquid that just needs the right width of a channel to flow through, but like a gas, that will simply fill all available space.

Maybe the OP or others can correct me if i'm being overly simplistic, but basically if you build a road or highway, it will fill up to a barely tolerable level of traffic within a few years. Double the highway? A few years you get double the traffic, it never solves anything. All that happens is that it encourages more people to drive, and allows more sprawl.

Wasn't there some case in NYC where they shut down some fairly important and very clogged street and all the traffic "experts" freaked out that it would clog all the nearby streets while a few locals say "nah, they'll just choose another way to get around" and not only did the neighbouring streets not experience the "over-flow" but overall traffic in the area improved?

If you build it, they will drive on it. If you don't built it, they'll walk or take the train. Cars are a pretty comfortable way of getting around, and if you make it too easy people are quickly seduced. Make driving not so pleasant, allow terrible traffic to act as a moderating factor, and people will get around another way. The key though, and what's lacking in north america, is that the "other way" is generally horrible or non-existing.

I bet you anything those dutch maps increase in traffic do not correspond to increases in population, but rather increases in highway capacity.

Neither gas nor liquid is a particularly apt analogy here, because both conserve mass - if you double the size of a pipe, the pressure of the gas should halve (everything else being equal), and the space between each individual molecule should increase. In the case of traffic, this is certainly true in the short term.

In the long term, however, it appears that "mass" itself is not conserved. The best analogy I can come up with is a fluid (liquid or gas) flowing out of a tank that is gradually getting fuller - the "pressure" to get from A to B grows slowly over time, and is roughly independent of the transit capacity. Building a bigger freeway just diverts relatively more people through it in comparison with other transit system; the overall demand is great enough that all systems will be used at their "maximum" capacity (assuming that all systems are well designed to meet that demand).

The real problem is that in a sufficiently dense population, it becomes effectively impossible to build capacity that exceeds demand - LA is living proof. The answer is obvious: in dense urban areas, focus on the most "dense" forms of transit (subways/el's), and minimize expenditures on much less "dense" freeway systems.

Unfortunately for the U.S., retrofitting urban areas to use subways or el's is prohibitively expensive if there was no consideration for them in the original city plan. This is not really a technical problem - it's a political one.

Edit: /\/\/\/\ Who would have thought, networking theory is better fit to describe a network of transit than trying to shoehorn crappy fluid flow analogies.

Jasper Tin Neck
Nov 14, 2008


"Scientifically proven, rich and creamy."

Baronjutter posted:

I've heard that traffic is not like a liquid that just needs the right width of a channel to flow through, but like a gas, that will simply fill all available space.
It's called the Lewis-Mogridge position. Many traffic designers agree with it, with some reservations.


Consider the simplest possible demand-supply situation. Intuitively, people would think that increasing supply (i.e. road capacity) would lead to smoother, "less expensive" traffic at price P1. (Remember, in economics, anything that bothers you enough that you'd pay for it to go away if you could counts as a cost.) But since there are people willing to start driving if it only got a little cheaper, you end up with traffic increasing to Qf at a price of Pf.


The exact amount of increase in traffic is dependent on the price-elasticity of driving i.e. how many units easier or cheaper does driving have to get to make people drive one unit more. If you have people who are willing to drive for relatively small improvements you get massively expanded traffic for only a slight reduction in crowding.

So far, so good, but traffic did get better, didn't it?

Baronjutter posted:

Maybe the OP or others can correct me if i'm being overly simplistic, but basically if you build a road or highway, it will fill up to a barely tolerable level of traffic within a few years. Double the highway? A few years you get double the traffic, it never solves anything. All that happens is that it encourages more people to drive, and allows more sprawl.
The graphs above assume static demand, which only exists in the short term. Economic growth alone means more people have more money to spend on driving, so demand has a tendency to grow over time.

Then there are strategic effects, which essentially entails sprawl. When traffic improves, longer commutes become viable and land further away from wherever people are going becomes more valuable. When it is developed, the new residential areas, malls and factories induce their own demand. And traffic has become just as bad as it used to be.

Public transport doesn't really work any differently, but because the catchment-radius of a transit stop is much shorter, growth tends to be vertical sprouting rather than horizontal sprawl. Trip distances don't grow as much because obviously the elevator ride three stories down is a hell of a lot shorter than walking/driving three houses over.

Hypothetically you could fund e.g. a rail route through increased property tax revenues near a stop, but since strategic effects are poorly understood and deeply entangled with politics, these kinds of considerations are extremely rarely taken into account in a benefit/cost-analysis.

PerryMason
Sep 6, 2005

I want a Dixieland Funeral

Cichlidae posted:

...
Back in 1960, AASHO (now called AASHTO, since they don't want to be called rear end-ho anymore) did some road tests, basically making a bunch of trucks drive in big ovals for months and months. The results of this test show how much load flexible (asphalt) and rigid (concrete) pavements can take before breaking down. They're all quantified in terms of the Equivalent Single Axle Load (ESAL), which is a single axle bearing 18,000 pounds.
...

http://maps.google.com/maps?q=utica...,165.11,,0,6.44

Interestingly enough, they turned that oval that trucks had to drive on for months/years into some sort of monument or shrine or something. There's no real way to get to it though outside of parking along the county road and crawling under the fence. It was kind of interesting to see how some of the pavement has held up over the past 50 years though... It ranged from still mostly intact to "I've seen gravel roads better than this".

Grand Fromage
Jan 30, 2006

L-l-look at you bar-bartender, a-a pa-pathetic creature of meat and bone, un-underestimating my l-l-liver's ability to metab-meTABolize t-toxins. How can you p-poison a perfect, immortal alcohOLIC?


Baronjutter posted:

Wasn't there some case in NYC where they shut down some fairly important and very clogged street and all the traffic "experts" freaked out that it would clog all the nearby streets while a few locals say "nah, they'll just choose another way to get around" and not only did the neighbouring streets not experience the "over-flow" but overall traffic in the area improved?

Not sure about NYC, but Seoul did. They took out a major highway to restore a stream, and not only did traffic not get worse, it decreased. Plus the stream is nice and improved the quality of life in the surrounding neighborhoods.

Mandalay
Mar 16, 2007

WoW Forums Refugee
San Francisco is pretty proud about removing downtown highways, too.

Echo 3
Jun 2, 2006

I have a bad feeling about this...

Baronjutter posted:

Wasn't there some case in NYC where they shut down some fairly important and very clogged street and all the traffic "experts" freaked out that it would clog all the nearby streets while a few locals say "nah, they'll just choose another way to get around" and not only did the neighbouring streets not experience the "over-flow" but overall traffic in the area improved?

You're probably thinking of Washington Square Park, which Fifth Avenue used to cut through until some time in the 60s, when Jane Jacobs and others managed to convince the traffic engineers to do a "trial" closing of the road through the park.

Of course all the engineers scoffed and said it would cause huge jams on the surrounding streets, because they just assumed that the same amount of car traffic would flow through the area, but lo and behold, traffic actually decreased! And so Washington Square Park remains car-free to this day.

Socket Ryanist
Aug 30, 2004

Mandalay posted:

San Francisco is pretty proud about removing downtown highways, too.
It's great for San Francisco but sucks balls for people who want to drive between the east bay and the peninsula via the bay bridge. There's no way to bypass the clusterfuck of people getting on or off 101/80 in downtown SF

Maybe they could remove most of the exits/entrances except for one big one at each end.

Blue Moonlight
Apr 28, 2005
Bitter and Sarcastic

Grand Fromage posted:

Not sure about NYC, but Seoul did. They took out a major highway to restore a stream, and not only did traffic not get worse, it decreased. Plus the stream is nice and improved the quality of life in the surrounding neighborhoods.

Portland, OR did a similar thing back in the 70s with Harbor Drive. It's now a park that spans much of the length of the waterfront downtown. Really, it was due to a conflux of anti-freeway sentiment and the completion of I-5 and I-405 which provided alternate (and more direct) routes.

Of course, now the city is overrun with a bunch of idiot bicyclists. Now, I know that there are plenty of responsible bicyclists in the city too, which is what makes the rest of them all the worse. On Friday, a guy went the wrong way up Broadway and blew through a red light, meaning I almost hit the rear end in a top hat as I came up Alder. When I honked, he gave me a look like I was the prick.

There's a Portlandia sketch that features the guy riding around the city on a bike screaming about how he's on a bike. It's easily the most accurate sketch on that show.

Nintendo Kid
Aug 4, 2011

by Smythe

Millstone posted:

Can anyone tell me why the New Jersey Turnpike and I-295 seem to parallel for several miles? Help me out here, I don't deal with many toll roads. It just seems highly counter-intuitive to run two freeways right next to each other.

The NJ Turnpike was built as an often close to arrow straight route between the simultaneously-in-construction Delaware Memorial Bridge original span (although really, it ends a few miles before and there's a separate shared freeway between US 40 and I-295 connecting it to the Turnpike) and access roads to the George Washington Bridge and Lincoln Tunnel into NYC (the original top end merged onto US 46 to get to the GWB, instead of curving around as freeway now). It was explicitly designed so traffic passing through would take it, as well as intrastate traffic.

I-295 was originally planned to be an upgrade and rerouting of US 130 to freeway standards. While the NJTP was built 1950-1951, the first section of I-295 opened as US 130's reroute in 1948, with the second portion of that in 1954 - to this day, US 130 and I-295 are concurrent through that stretch, and there's frontage roads and frequent exits to serve the surrounding business and homes on old 130. Later on, in 1963, I-295 was completed from a divergence in part of the US 130 freeway down to and over the Delaware Memorial Bridge. Then through the 70s, 80s and 90s it was completed northward to where it ends at North I-295 turning into South I-95, looping over Trenton into PA.

Now, originally, I-95 was planned to go northwest from above Trenton through some suburbs and rural areas to merge onto I-287 and then onto the Turnpike, with I-95 providing an alternate, more westerly connection from the Philly area to the NYC area, and I-295 providing a semi-loop bypass of I-95 that went through NJ and avoided all the congested freeway through Philadelphia. But that leg of I-95 got canceled due to residents complaining about trucks and such taking it - stupid assholes, as instead all those trucks and such are barreling down surface roads in the area instead of behind nice sound barriered freeways. Can you tell I'm bitter about this? I grew up in a town in that area that always had annoying truck traffic since the "Somerset Freeway" never happened.

Anyway I guess that is an old post, but I've been reading through this thread since I joined and I-295 covers some things I wanted to ask the OP about!

Cichlidae posted:



OP, since I know you LOVE terrible interchanges, and not otherwise sane ones that look a bit confusing, check this out:



Now at first you might say, what is so bad? But take a closer look. Look at the path South 295 has to take through this (even though it's more of a west direction in this particular area) for example. Notice how there's missing movements between the freeways.

And then check out street view! Here's going north through the interchange: http://g.co/maps/3xp4c
Northbound 295 has just merged in on the right hand side to where 42 ends and I-76 begins (even though 76 may as well be continuous to at least the Atlantic City Expressway entrance, but I digress). Northbound 295 is also about to "exit" out through a lovely curve, and in the meantime people are weaving like crazy to get from North 42/76 to North 295 and vice versa.

Ever so slightly saner on the southbound side: http://g.co/maps/6pbd3
At least here there's a solid barrier between 42/76 traffic and 295 traffic. However to get to 42 from this, you're making a tight left exit up ahead while 42 has a flyover left exit that merges into south 295. However to get to this point you've already gone through a 35 mph 270 degree curve just after a 2 lane lane left exit: http://g.co/maps/veprn

Have I mentioned that on both sides 295, which is 3 lanes and 55 mph on either side of the interchange, gets cut to 2 lanes through and both ways have large segments with 35 mph speed limits as well as curves with 35 mph speed warnings? For further clarity, see miles 26-29 on the NJ SLD for it (does Connecticut put up their SLDs publically by the way?) http://www.state.nj.us/transportation/refdata/sldiag/00000295__-.pdf and the enlarged view PDF http://www.state.nj.us/transportation/refdata/sldiag/enlarged_view_27.pdf

So here's my question: who the gently caress thought this was a good idea??? Such lovely design features as ensuring that any accidents on I-76 or I-295 Northbound above the interchange will cause backups down all the roads involved, or I-295 and NJ 42 Southbound for the reverse. Requiring a major 3 lane per side interstate to cut to 35 MPH and 2 lanes and go around huge curves in one direction, and 2 lanes, lesser curves, 35 mph speeds and a horrific merge/weave abomination in the other. Is the I-295/I-76/NJ 42 interchange proof that road engineering god is real and he is evil?

(There's a happy ending though! They're currently in the final planning and initial construction stages of the replacement: http://www.state.nj.us/transportation/works/studies/rt295/shortlist-alternatives_mapD.shtm )

Now with that out of the way, how do you feel about the project underway that's finally ending the I-95 gap? It's even been in actual construction for a year now! http://en.wikipedia.org/wiki/Pennsylvania_Turnpike/Interstate_95_Interchange_Project

I-95 will be getting an interchange with, and routed over, the eastern part of I-276 of the PA turnpike, and thence over a doubling of the current PA Turnpike-NJ Turnpike bridge and the PA extension of the NJ Turnpike to the mainline. I-295 will end at I-195, I-195 gets extended over what is now 295 and 95 and over to where the PA Turnpike interchange will be, thus ending having North 295 turn into South 95 over US 1:

Another result of that, is that the dual-dual system is being extended from Exit 8A all the way down to Exit 6 (the connector to the PA Turnpike) http://www.njturnpikewidening.com/

As a traffic guy, how do you feel about accommodating and supporting these kinds of projects? How does it get decided which overpasses and roads get kept open while their replacement is constucted alongside and which get demolished before the replacement is built (this is something I see when I drive down to South Jersey through this!). And do you think more roads would be better off as dual-dual systems instead of just having a lot of lanes on each side?

(thanks for the cool thread by the way!!)

Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...
I just wish SOMETHING would be done about The Merge near exit 8A. You know which one I mean

Nintendo Kid
Aug 4, 2011

by Smythe

Volmarias posted:

I just wish SOMETHING would be done about The Merge near exit 8A. You know which one I mean

Well the merge is going shunted down to below Exit 6 since they're carrying the dual-dual down there, and between 6 and 5 the road will be 4 lanes each direction as part of a separate widening project to ease merging coming out of that.

Volmarias
Dec 31, 2002

EMAIL... THE INTERNET... SEARCH ENGINES...

Install Gentoo posted:

Well the merge is going shunted down to below Exit 6 since they're carrying the dual-dual down there, and between 6 and 5 the road will be 4 lanes each direction as part of a separate widening project to ease merging coming out of that.

Yeah, but more short term extending the four lanes section an extra mile by taking over some shoulder would be wonderful. Six lanes into three :negative:

Grand Fromage
Jan 30, 2006

L-l-look at you bar-bartender, a-a pa-pathetic creature of meat and bone, un-underestimating my l-l-liver's ability to metab-meTABolize t-toxins. How can you p-poison a perfect, immortal alcohOLIC?


My favorite awful merge from my hometown.



The I-75/I-35 interchange. The magic happens when you're traveling north on 75 and want to start going east on 35. Can you see it?







Right there. The red line is going from 75 to 35. You're traveling at highway speed here. The blue line is an on-ramp that goes to 35 west. To negotiate this, you have to get off 75 onto this raised road, speed along the concrete barriers, go into a short section (lasts maybe ten seconds) without barriers, cross over from the left lane to the right lane while the blue traffic is also crossing from the right lane to the left lane (or staying right to go east), and do it before the next concrete barrier pops up and kills you. Also, there is virtually always construction here so there are barrels everywhere and the shoulders are closed.

Adbot
ADBOT LOVES YOU

Dr Jankenstein
Aug 6, 2009

Hold the newsreader's nose squarely, waiter, or friendly milk will countermand my trousers.

Install Gentoo posted:

gently caress 295 where it meets 76

I'm moving to Blackwood next month. (moving literally right off of 42, too)

I will be taking Black Horse Pike to 295 (I work in Cherry Hill) every day just avoid the insanity that is 295/76/42 all meeting up at the same drat spot. It is, quite possibly, the most poorly designed mile or so of roadway ever. You know you've designed something poorly when people who live ~1 mile from the entrance to a freeway would rather drive 4 miles out of their way, and sit through 7 zillion stoplights than deal with your horrible freeway design.

I used to take 130 to 295 every day though...for a 45 minute commute it was so effortless. (outside of the lights on 130, it was such a smooth, easy drive...130/295 just sort of effortlessly combine just south of Bordentown)

Dr Jankenstein fucked around with this message at 05:53 on Nov 14, 2011

  • 1
  • 2
  • 3
  • 4
  • 5
  • Post
  • Reply