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samagon

More lanes = More cars

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http://www.wired.com/2014/06/wuwt-traffic-induced-demand

 

From time to time Wired has decent articles, this is one of those.

 

 

In 2009, two economists—Matthew Turner of the University of Toronto and Gilles Duranton of the University of Pennsylvania—decided to compare the amount of new roads and highways built in different U.S. cities between 1980 and 2000, and the total number of miles driven in those cities over the same period.

“We found that there’s this perfect one-to-one relationship,” said Turner.

If a city had increased its road capacity by 10 percent between 1980 and 1990, then the amount of driving in that city went up by 10 percent. If the amount of roads in the same city then went up by 11 percent between 1990 and 2000, the total number of miles driven also went up by 11 percent. It’s like the two figures were moving in perfect lockstep, changing at the same exact rate.

 

worth reading, their suggestion is congestion charge, not a bad idea, but as it relates to Houston, not really feasible until alternate forms of transit are introduced. Doesn't do much good to have something like congestion charging if there are no other options available, and their examples of cities that have congestion charging, or have proposed it have very good alternate transit options. Also, the cities where they have successfully removed freeways had other transit options available as well.

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Did they account for population as well, or is this just one of those "bend statistics the way we want to" kind of things?

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they didn't expand on that, but to me it makes sense.

 

let's take 2 scenarios, one where it would take 30 minutes to drive 5 miles, and one where it only takes 10 to drive the same 5 miles.

 

I'm more inclined to stack stops on the 30 minute 5 mile scenario, so if I go grocery shopping once a week, I'll not go to academy during the week to buy some new work out shorts, I'll go on the same day I go grocery shopping. So I'd end up with like, 3 or 4 places to visit on one trip.

 

In the second scenario, I'll just go when the need strikes, so I may go to the grocery store twice a week, or go specifically to academy to buy the shorts. taking more trips.

 

This doesn't work when you think specifically of commuting, but realistically, that's just 5 round trips a week I take, vs the 20 or so random other round trips I take. If congestion (or congestion charging) was high enough, I'd even be inclined to pack some of those trips into the second half of the commute trip. Even making the commute more efficient.

 

So the population is far less dynamic of a factor than the number of trips that any individual would take, and as congestion increases (or other costs of the trip, not just the time), so does the incentive to take fewer trips.

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One of the advantages of congestion charges is giving people a financial interest to shift their commute patterns to move outside of the traditional peak times.  For example, if congestion pricing convinces x% of people to move to a 6am - 3pm schedule instead of an 8am - 5pm schedule, you have a significant reduction in congestion.  That's a potential immediate impact regardless of transit alternatives.

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One of the advantages of congestion charges is giving people a financial interest to shift their commute patterns to move outside of the traditional peak times. For example, if congestion pricing convinces x% of people to move to a 6am - 3pm schedule instead of an 8am - 5pm schedule, you have a significant reduction in congestion. That's a potential immediate impact regardless of transit alternatives.

It's not up to the person it's up to the job

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It's not up to the person it's up to the job

Not always. I can start work any time between 6 and 9.

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Oh so because you can, everybody else can too. Good point.

 

You're not trying to shift everyone, you're just trying to shift a percentage.

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You're not trying to shift everyone, you're just trying to shift a percentage.

You don't think that would've been done by now? Fact is there will always be rush hour traffic. For most jobs you need to be at work durin certain hours so you are accessible.

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You don't think that would've been done by now? Fact is there will always be rush hour traffic. For most jobs you need to be at work durin certain hours so you are accessible.

 

There will certainly always be rush hour traffic and roads will be at capacity at that time.  The question is whether you can increase the utilization of roads during off-peak hours to maximize efficiency.  While I agree that most people need to be at work during certain hours, what those hours are can definitely vary depending on the role.  If a high percentage of your work that involves collaboration with the West Coast, those hours that you need to be at work are different than if you collaborate locally.  A 10-7 schedule is highly desirable for the company in that situation.

 

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The stick (congestion charge) isn't the only option, and (hopefully) it wouldn't be implemented as the sole means of changing habits.

 

you'd hope for a carrot as well.

 

Offer incentives to companies that take steps to reduce traffic during peak times. Work from home (if possible), different work schedules (4/10), different work hours, incentives for taking public transportation, or carpooling (I think this one's already being done). There's lots of opportunity.

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The stick (congestion charge) isn't the only option, and (hopefully) it wouldn't be implemented as the sole means of changing habits.

 

you'd hope for a carrot as well.

 

Offer incentives to companies that take steps to reduce traffic during peak times. Work from home (if possible), different work schedules (4/10), different work hours, incentives for taking public transportation, or carpooling (I think this one's already being done). There's lots of opportunity.

 

Work from home seems to be the piece that is commonly ignored in transportation discussions.  There was considerable coverage of Yahoo's decision to abandon a flexible work schedule, but the only reason that it even deserved any coverage is that it was one company moving counter to the rapidly growing trend. 

 

Huge value in providing tax incentives to companies that support work from home and flexible work schedules.

 

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It makes sense.  More parking spaces also = more cars.  That's one of the reasons new office skyscrapers in Chicago no longer incorporate parking garages.  If people don't want to take transit, make them pay a premium to park in the remaining garages.

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Work from home seems to be the piece that is commonly ignored in transportation discussions.  There was considerable coverage of Yahoo's decision to abandon a flexible work schedule, but the only reason that it even deserved any coverage is that it was one company moving counter to the rapidly growing trend. 

 

Huge value in providing tax incentives to companies that support work from home and flexible work schedules.

 

 

 

It hasn't been announced yet, but my company is another one that is about to strongly rein in on people working from home.  It's been prone to abuse, but to me the biggest problem is that is cuts people off from day-to-day interaction in which problems get discussed and solved.  Once employees get out of that loop their careers noticeably suffer.  I suppose it depends on the specific nature of the work however.  After having seen it in action I'm convinced that remote working will remain a non-starter for the majority of companies and employees.  

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I hear a lot more barking dogs and clamoring children on work related calls than I used to.  Fortunately, I've got the flexibility to start my work day at home for an hour or two and then head in after traffic, the occasional early fixed time commitment aside.  On a day in, day out basis, though, I could sure see the household projects becoming a major distraction.

 

Subdude's right, too - if the work involves collaboration, it really helps to have the one on one face time.  

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Work from home seems to be the piece that is commonly ignored in transportation discussions. There was considerable coverage of Yahoo's decision to abandon a flexible work schedule, but the only reason that it even deserved any coverage is that it was one company moving counter to the rapidly growing trend.

Huge value in providing tax incentives to companies that support work from home and flexible work schedules.

Again what percentage of jobs can work at home? If you're not in the office speed to connect to the server is considerably slower as well. It's usually an out for people that just don't want to come to the office. They are the first to let go and possibilities for advancement are shuttered also.

It hasn't been announced yet, but my company is another one that is about to strongly rein in on people working from home. It's been prone to abuse, but to me the biggest problem is that is cuts people off from day-to-day interaction in which problems get discussed and solved. Once employees get out of that loop their careers noticeably suffer. I suppose it depends on the specific nature of the work however. After having seen it in action I'm convinced that remote working will remain a non-starter for the majority of companies and employees.

This

There will certainly always be rush hour traffic and roads will be at capacity at that time. The question is whether you can increase the utilization of roads during off-peak hours to maximize efficiency. While I agree that most people need to be at work during certain hours, what those hours are can definitely vary depending on the role. If a high percentage of your work that involves collaboration with the West Coast, those hours that you need to be at work are different than if you collaborate locally. A 10-7 schedule is highly desirable for the company in that situation.

There is also a central and eastern time zone....

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Nice to hear anecdotal evidence, but the numbers don't agree with the anecdotes.  The 2010 census reported a 41% increase in work from home over the 2000 census with almost 10% of workers working from home at least one day a week.

 

http://money.cnn.com/2012/10/04/news/economy/work-from-home/

 

67% of companies allow at least some employees to work from home, up from 50% in 2008 with 38% of employees allowing at least some employees to work from home on a regular basis.

 

http://www.marketwatch.com/story/its-getting-easier-for-boomers-to-work-at-home-2014-05-28

 

Houston had a higher percentage of workers that worked from home in 2012 than used public transit to commute (3.5% vs. 2.6%)

Dallas-Ft. Worth had over 3x as many workers work from home in 2012 than used public transit to commute (4.6% vs. 1.5%)

 

http://www.demographia.com/db-2012jtw.pdf

 

 

 

 

 

 

 

Edited by livincinco

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Oh so because you can, everybody else can too. Good point.

 

Where the heck do you get that from that simple statement?

 

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Nice to hear anecdotal evidence, but the numbers don't agree with the anecdotes. The 2010 census reported a 41% increase in work from home over the 2000 census with almost 10% of workers working from home at least one day a week.

http://money.cnn.com/2012/10/04/news/economy/work-from-home/

67% of companies allow at least some employees to work from home, up from 50% in 2008 with 38% of employees allowing at least some employees to work from home on a regular basis.

http://www.marketwatch.com/story/its-getting-easier-for-boomers-to-work-at-home-2014-05-28

Houston had a higher percentage of workers that worked from home in 2012 than used public transit to commute (3.5% vs. 2.6%)

Dallas-Ft. Worth had over 3x as many workers work from home in 2012 than used public transit to commute (4.6% vs. 1.5%)

http://www.demographia.com/db-2012jtw.pdf

3-4% is a drop in the bucket and it's convenient to use cities that have mediocre transit systems for your argument Edited by Slick Vik

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3-4% is a drop in the bucket and it's convenient to use cities that have mediocre transit systems for your argument

Got it. So just to clarify, your stance is that mass transit with a 5.0% national share of workers is vitally important and that work at home with a 4.4% national share of workers is a drop in the bucket? Maybe we should just focus then on improving the 9.7% national share that carpooling possesses which is one of the proven benefits of congestion pricing.

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Got it. So just to clarify, your stance is that mass transit with a 5.0% national share of workers is vitally important and that work at home with a 4.4% national share of workers is a drop in the bucket? Maybe we should just focus then on improving the 9.7% national share that carpooling possesses which is one of the proven benefits of congestion pricing.

I don't see an improvement for carpooling. Improving transit can lead to up to a 55% market share which dwarfs both of those numbers.

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I don't see an improvement for carpooling. Improving transit can lead to up to a 55% market share which dwarfs both of those numbers.

 

I'm going to remove myself from this conversation, because I really just have no interest in further wasting my time listening to you plod through your standard tedious monologue about how everything good and meaningful in this world is caused by rail.  Have a nice day.

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I wonder what percentage of drivers (like me), absolutely have to have their cars for work. It's not just a simple, home to office and back commute. I would assume real estate agents, contractors, and of course delivery companies that have vehicles.

 

But then again my work takes me along the ship channel and not in any of the business districts. Although I do drive through them, just not a destination.

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I don't see an improvement for carpooling. Improving transit can lead to up to a 55% market share which dwarfs both of those numbers.

 

Doesn't matter in this discussion. Houston has really bad mass transit, yes, we need it.

 

Problem is, if this study is correct, which I believe it is, adding a congestion charge, and adding a few carrots for companies and motorists may help provide a bit of relief, and the money collected from the congestion charge could go to improving transit, and provide better maintenance on the roads we drive now.

 

The rather simple discussion point of the article is "If you add more lanes in an effort to reduce traffic, all you do is encourage people to use their cars less efficiently".

 

If you think that adding mass transit options would magically make people want to take mass transit, you're mistaken. Yes, some would shift, but the majority would not.

 

Look to europe for a case in point, in the countries, and cities where there is no congestion charges traffic is horrendous. The Netherlands are a terrific example, they have a world class mass transit network including local bus service, trolley lines, subway, commuter rail, long distance commuter rail, they have it all, but then they also have a really terrific road network, and whenever they upgrade the road network, more people shift to driving cars. 

 

You cannot just give people a mass transit solution and expect them to walk away from their cars.

Edited by samagon
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This point that the article makes:

 

 

Interestingly, the effect works in reverse, too. Whenever some city proposes taking lanes away from a road, residents scream that they’re going to create a huge traffic snarl. But the data shows that nothing truly terrible happens. The amount of traffic on the road simply readjusts and overall congestion doesn’t really increase.

 

is exactly why I've argued for blowing up the Pierce Elevated.  People will claim that doing so would cause horrendous traffic jams, but traffic would simply readjust.  In the example of the Pierce Elevated we even have a real-life test case from when it was rebuilt in the 1990s.  There were all kinds of scary prophecies of traffic doom, but after a day or so drivers just kind of figured it out and it worked out fine.

 

 

 

 

 

 

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I contend that because the data is inherently flawed, any "suggestions" (like congestion pricing) made are not as important as they characterize them to be (that's not to say that congestion pricing is worthless). The media loves stories like this because they can generalize and get viewers, even if the science was not fatally flawed to begin with. And that's the joy of statistics, that with the right cherry-picked variables you can practically make up whatever you want, and if there's not what you want, you can play around with the amorphous "linked with" to make up your own conclusions. Light rail is linked with higher density. Higher density is linked with higher crime. Therefore, light rail is linked with higher crime!  ^_^

 

(P.S.: I know there's all sorts of things wrong with "light rail is linked with higher crime", but keep in mind that was for example purposes only and not an invitation to bombard me on how wrong I am)

Edited by IronTiger

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The article doesn't present any description of the underlying data, the means of analysis, or the resulting stats at all, so I don't see how it is possible to draw a conclusion based on the validity of the data one way or another.  I was just going by what was written.  If you are contending that the data are flawed you should at least explain the basis for that conclusion, rather than just tossing it out as a given and then extrapolating away.  

 

Mind you, I'm not saying the data or methodology are perfect, there's just no basis to assume one way or another, including concluding that the researchers cherry-picked variables.  

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The article doesn't present any description of the underlying data, the means of analysis, or the resulting stats at all, so I don't see how it is possible to draw a conclusion based on the validity of the data one way or another.  I was just going by what was written.  If you are contending that the data are flawed you should at least explain the basis for that conclusion, rather than just tossing it out as a given and then extrapolating away.  

 

Mind you, I'm not saying the data or methodology are perfect, there's just no basis to assume one way or another, including concluding that the researchers cherry-picked variables.

The "induced demand" theory is hardly groundbreaking, and follows that as new roads are built, development comes to it, and the net result is nothing. Except a few bypasses don't actually get that type of development until years down the road, which would still "prove" the theory.

Problem is, the "lurking variable" in all this is population. Houston has a lot of roads. Houston has a lot of traffic. But it also has a lot of people. Are people drawn by the roads? Maybe, maybe not. They're drawn because the city as an economy.

The Katy Freeway is a popular example on why the induced demand theory works, but the Katy Freeway is proof that it doesn't work. The Katy Freeway was built in the 1960s on an existing highway. Over the years, as the city of Houston grew along that corridor, traffic worsened, even though it hadn't added any lanes (save for a reversible HOV).

Detroit is another example, having given its roads roomy widenings back in better times. Those roads, of course, are not congested, because the population shrank.

Nearly every city that has expanded its highway system in the last 30 years has gained population, a very vital thing that these researchers seem to be forgetting.

"But why do people drive farther?" you may ask. Typically, cities with good economies draw people from a wide radius. Many people drive 1-2 hours each way just to work in Houston, because it has a good economy. It has jobs. To blame the long driving on highway width is absolutely ridiculous.

There are limits to how wide freeways can get, of course, and mass transit gets more efficient with density, and there are freeways that could probably be removed that don't actually affect the traffic flow.

But it is wrong to foster a belief that highway width "causes" traffic or that you could hack out any freeway you choose with little consequences, because traffic just doesn't work that way.

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The question that I've never seen answered about induced demand is what the coorelation is to economic growth. Taking the Katy Freeway example, yes there is more traffic after the expansion, but it's also pretty obvious that West Houston has been in a prolonged boom since it was completed. So it's great to argue that removing a highway doesn't cause congestion but I haven't been able to find any evaluation of the economic impact of that removal and would be very curious to see a non-biased study of that subject.

I fully expect the anecdotal responses, but those aren't studies.

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The question that I've never seen answered about induced demand is what the coorelation is to economic growth. Taking the Katy Freeway example, yes there is more traffic after the expansion, but it's also pretty obvious that West Houston has been in a prolonged boom since it was completed. So it's great to argue that removing a highway doesn't cause congestion but I haven't been able to find any evaluation of the economic impact of that removal and would be very curious to see a non-biased study of that subject.

I fully expect the anecdotal responses, but those aren't studies.

Or the economy picked up around the time parts of it completed. Had it fully completed in the heart of the recession its economic impact would be zero. Edited by Slick Vik

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Or the economy picked up around the time parts of it completed. Had it fully completed in the heart of the recession its economic impact would be zero.

Have I ever told you how impressive it is that you can be 100% certain of a completely hypothetical situation? Kind of reminds me of Stephen Colbert's comment about George Bush - "He believes the same thing on Wednesday that he believed on Monday. No matter what happens on Tuesday."

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Or the economy picked up around the time parts of it completed. Had it fully completed in the heart of the recession its economic impact would be zero.

Actually it started to wrap up just as the recession started. It's laughable that you'll go out of your way to try to discredit freeways as being worthless.

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Actually it started to wrap up just as the recession started. It's laughable that you'll go out of your way to try to discredit freeways as being worthless.

It still hasn't wrapped up. There is construction around shepherd even now.

Have I ever told you how impressive it is that you can be 100% certain of a completely hypothetical situation? Kind of reminds me of Stephen Colbert's comment about George Bush - "He believes the same thing on Wednesday that he believed on Monday. No matter what happens on Tuesday."

So massive investment was being made during the recession?

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It still hasn't wrapped up. There is construction around shepherd even now.

The big highway with "too many lanes" west of 610 is the one I'm referring to and the one that's often cited. You're trying to change the goalposts to try to make your point, which isn't working.

Point is, "induced demand" just takes two pieces of evidence and attempts to make it truth without taking into other variables. I've also found that the main people who use the "induced demand" argument happen to be fans of mass transit.

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The big highway with "too many lanes" west of 610 is the one I'm referring to and the one that's often cited. You're trying to change the goalposts to try to make your point, which isn't working.

Point is, "induced demand" just takes two pieces of evidence and attempts to make it truth without taking into other variables. I've also found that the main people who use the "induced demand" argument happen to be fans of mass transit.

I never changed the goalposts I referred to the project as a whole.

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It still hasn't wrapped up. There is construction around shepherd even now.

 

 

The Katy Freeway widening wrapped up in 2009 and the project's borders were from the Ft. Bend county line to Washington Ave. The project you're referring to around Shepherd has nothing to do with the 03-09 Katy Freeway widening.

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Or the economy picked up around the time parts of it completed. Had it fully completed in the heart of the recession its economic impact would be zero.

 

Actually, the katy freeway is a terrific example of the whole point of the article.

 

Increase the lanes on the freeway and it will be used more frequently.

 

It's no secret that people bemoan that after the expansion that the drive times on the freeway are just as bad as they were pre-expansion. So what was gained by adding 20 lanes on each side?

 

There's a good point in his post though, increase the density of the traffic and you increase the commerce that will naturally occur on that corridor. Same as how rail ridership should increase the commerce because it's a denser form of transit, to deny that one has this effect and that the other does not, that's just silly.

 

As an anecdotal point to the katy freeway, my family lives in Alief, and I have many friends who still live there. Prior to the expansion, I chose 59 as the means to get from my house in the east end to my parents, or friends, but after construction was completed, I find myself using Katy fwy rather than 59.

Edited by samagon
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Exactly, there seems to be an assumption that if you remove capacity, the balance of the network just "absorbs" the capacity, but that seems to be a very questionable assumption to me. It's also quite likely that decreased capacity causes workers and/or companies to locate elsewhere which would cause a reduction in the economic productivity of the area.

I truly haven't seen any analysis of that and it seems to be a rather obvious question.

Edited by livincinco

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Exactly, there seems to be an assumption that if you remove capacity, the balance of the network just "absorbs" the capacity, but that seems to be a very questionable assumption to me. It's also quite likely that decreased capacity causes workers and/or companies to locate elsewhere which would cause a reduction in the economic productivity of the area.

I truly haven't seen any analysis of that and it seems to be a rather obvious question.

Has this reduction happened in San Francisco?

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Problem is, removing freeways really is an unknown and needs more studying to make sure it could be done carefully. There aren't very many highway removal projects, ever: a few of them (Milwaukee, Portland) involved removing an older pre-Interstate road when it redundant (yet are often touted as "freeway removal"), Boston relocated theirs entirely underground (which didn't actually "remove" a freeway, actually replacing an old 1940s viaduct with a new one), San Francisco's freeways were only spurs to begin with and structurally compromised, and Seoul's freeway we really don't know a whole lot about the traffic patterns (Google Earth suggests that the surface streets were always more popular) or its structural integrity (it was built over a river, after all).

 

Assuming that something is the case based on a few rare examples of an already-rare event is just a rather shaky assumption. The only way to really "prove" something is if we start closing off a lot of freeways to measure any economic effects, and even if "hey, freeways are worth something", we would have destroyed economies in the process.

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