Custis Trail Riders – Take the VDOT I-66 Survey

[baiskeli]

@DismalScientist 9794 wrote:

The DC area has certainly not kept up with road building to match population growth.

Look at the numbers from the Texas Transportation Institute.

Not that I am advocating it do so. All I am saying is that expanding I-66 within the walls is the least-cost way (especially to Arlington) of expanding the transportation network. Furthermore, the deal restricting I-66 has only exacerbated its detrimental effects on Arlington.

Okay. I was just responding to your other comments.

As far are the development statement, I was responding to a comment suggesting that Westover would be destroyed by development caused by widening 66. baiskeli, you live across the freeway from me. Do you really think that development associated with widening the highway is a greater threat to neighborhood than the potential Clarendonation caused by development spurred by Metro?

No, I’m saying I’d much rather have more Clarendon than more freeway.

P.S. My house already is only a block from the highway. Traffic on Washington Blvd bothers me a lot more than traffic on I-66.

And I understand your point about traffic diversion. It’s a legitimate point, though I’m not sure it’s as big a factor as you do. And as I think someone mentioned, without systemwide improvements like widening the bridges, widening I-66 just moves the chokepoints so that you have a 3-lane traffic jam instead of a 2-lane one.

[DismalScientist]

@baiskeli 9793 wrote:

We could keep going with arguments in the extreme though, like this: Arlington would be paradise if I-66 were 14 lanes wide.

False dilemma. They may not be stupid. They could be simply misinformed, or relying on faulty or incomplete knowledge, or acting on their own interests to the expense of others. And their views don’t prove anything anyway. Pavement affects congestion a certain way regardless of how people think it does or doesn’t.

As you know, individuals sometimes act in their own rational self-interest in ways that result in hurting their interests when their individual actions are taken collectively.

1) I certainly don’t advocate widening I-66 outside the walls.

2) Stupidity and ignorance is observationally indistinguishable. I don’t want to argue that I am smarter or more informed than people making decisions in what I presume is their view of their self-interest.
The argument explicity states that people are not acting at the expense of others, but rather are acting against their own stated self-interest.

[DismalScientist]

@baiskeli 9797 wrote:

Look at the numbers from the Texas Transportation Institute.

No, I’m saying I’d much rather have more Clarendon than more freeway.

And I understand your point about traffic diversion. It’s a legitimate point, though I’m not sure it’s as big a factor as you do. And as I think someone mentioned, without systemwide improvements like widening the bridges, widening I-66 just moves the chokepoints so that you have a 3-lane traffic jam instead of a 2-lane one.

1) Cite please?

2) Not sure I agree with you on this, but it is a matter of opinion.

3) Exactly my point. I would much rather have a three lane traffic jam on I-66 than a two-lane traffic jam on I-66 and a traffic jam on Washington Blvd. The argument is even better if they don’t expand the bridges, because that way you don’t get added traffic from making easier to actually get from DC from Fairfax by car.

[americancyclo]

@Justin Antos 9790 wrote:

How would you measure capacity – vehicles per lane per hour? Or passengers per lane per hour? I’d argue the latter measure is superior.

That’s an interesting way to look at it, as far as the road potential to move people. I think when I see arguments about 66 being ‘at capacity’ I think they are saying that they are stuck in traffic. I wonder how often the idea that the potential number of people could be 4x greater than traffic with single occupant only is really addressed?

[baiskeli]

@DismalScientist 9799 wrote:

2) Stupidity and ignorance is observationally indistinguishable. I don’t want to argue that I am smarter or more informed than people making decisions in what I presume is their view of their self-interest.
The argument explicity states that people are not acting at the expense of others, but rather are acting against their own stated self-interest.

You’re right, your science is dismal!

All I mean to say is that what appears to be the best choice isn’t always the simplest or most intuitive. That’s not arrogant or superior. Problems can have objective solutions (thought maybe not this one) and nobody has perfect information or knowledge.

Also, people naturally think of solutions for themselves, but don’t factor in the fact that everyone else has the same idea, rendering their idea not so effective. People used to move to the suburbs to “escape traffic.” They forgot that everyone else was going to move there to escape too. And on top of that, now they’re all further from their jobs and living in places where it’s harder to get around without driving.

Thanks for providing a countervailing view on this interesting issue by the way – a bunch of people agreeing on everything would be boring as heck.

[DismalScientist]

@DismalScientist 9801 wrote:

1) Cite please?

I’ll give my own cite: http://mobility.tamu.edu/files/2011/10/complete-data.xls

The data show that freeway lane miles per capita increased by 20% from 1982 to 1990 and have since fallen to 1982 levels Per capita arterial lane miles have fallen 30% from 1982 to 2010.

[baiskeli]

@DismalScientist 9801 wrote:

1) Cite please?

This is the report I got the data from:

http://mobility.tamu.edu/ums/

I don’t have what I extracted from it now though. If you’re interested you could look, but I won’t expect you to accept my assertion just by throwing you a link.

As I recall, the data showed major highway lanes growing at about the same rate as population over the last two decades, but with vehicle-miles traveled per person growing by more than 50%. I believe that this reflects development patterns – people live further out and have to drive further to get to their jobs, and the outer suburban developments are more car-dependent so they don’t have alternative modes to get to work or anywhere else. (It also probably reflects greater wealth.)

To be fair, the metro areas used to measure all these things changed over time, bringing outer, more rural counties into the data.

I will try to dig out my data, I saved it somewhere, or go find it again on this report. My data were from a couple years ago. You can download a spreadsheet with all the data and mess with it.

2) Not sure I agree with you on this, but it is a matter of opinion.

Yes. As long as we both know that we’re likely to get one or the other.

3) Exactly my point. I would much rather have a three lane traffic jam on I-66 than a two-lane traffic jam on I-66 and a traffic jam on Washington Blvd. The argument is even better if they don’t expand the bridges, because that way you don’t get added traffic from making easier to actually get from DC from Fairfax by car.

Sure, but it’s more complicated than that, for instance, we could deal with the problem by taking more cars off the road in the first place and not have to choose between those two. We are building a Metro line out to the west as we speak, for instance.

[baiskeli]

@DismalScientist 9807 wrote:

I’ll give my own cite: http://mobility.tamu.edu/files/2011/10/complete-data.xls

The data show that freeway lane miles per capita increased by 20% from 1982 to 1990 and have since fallen to 1982 levels Per capita arterial lane miles have fallen 30% from 1982 to 2010.

Hey! You beat me.

Okay, I did a little calculating too, and yes, it increased but then fell to 1982 levels – meaning overall it kept up with population growth since 1982, just as I said.

Yet congestion has greatly increased since 1982. So that discounts population growth outpacing roads as a cause of the increase in congestion in that period. (With the caveat that the DC data collection region has added a few outer counties in that time).

Now divide daily vehicle miles traveled by population for each year, giving you the average number of miles each person travels in a car. That has grown by 47% since 1982. That’s a huge increase.

So if I’m doing the math right, it looks to me like the problem isn’t population growth, but the fact that people simply drive more.

[DismalScientist]

@baiskeli 9811 wrote:

Hey! You beat me.

Okay, I did a little calculating too, and yes, it increased but then fell to 1982 levels – meaning overall it kept up with population growth since 1982, just as I said.

Yet congestion has greatly increased since 1982. So that discounts population growth outpacing roads as a cause of the increase in congestion in that period. (With the caveat that the DC data collection region has added a few outer counties in that time).

Now divide daily vehicle miles traveled by population for each year, giving you the average number of miles each person travels in a car. That has grown by 47% since 1982. That’s a huge increase.

So if I’m doing the math right, it looks to me like the problem isn’t population growth, but the fact that people simply drive more.

But population growth almost implies per capita growth in person miles if all that growth means an expanded developed area (i.e. it is all not increased density). It’s hard to model, but as the developed area grows, the distance between home and some interesting destination for the average person must grow, implying greater travel per person.

[zanna_leigh]

@dasgeh 9651 wrote:

I think one of the ways you can lessen the number of cars on the road is to make driving miserable. Another is to make it expensive.

Hallelujah! I know this is an old article but it’s relevant.

http://www.nytimes.com/2011/06/27/science/earth/27traffic.html?pagewanted=all

“Urban planners generally agree that a rise in car commuting is not desirable for cities anywhere.”

[DismalScientist]

@dasgeh 9744 wrote:

I can think of lots of ways to spend the money they would spend widening I-66 to encourage cycling: build overpasses/tunnels to reduce grade crossing, install HAWK signals, launch a driver (and cyclist) education campaign, increase cycling tax credits (there’s already a small one for employer-provided cycling stipends, similar to the public transit one – hands up if anyone gets it), build more cycletracks, expand CaBi.

I don’t see these as trade-offs with expenditures on transportation infrastructure.
1) Get rid of at grade crossings: How many opportunities are there for this: Lynn and Lee highway? Any others?
2) HAWK signals: Good idea; should be standard on all trail crossings of busy roads. Is lack of funding what is causing these not to be installed?
3) Driver education: Good idea. Area drivers treat everyone like crap, not merely cyclists and pedestrians. Should be done regardless of spending on infrastructure.
4) Subsidies for cyclists: We are trying to target drivers who refuse to switch to Metro for a subsidy. Do you really think that these folks will switch to cycling for a similar subsidy? Cycling is practically free compared to the costs of driving and parking already. For these subsidies to be effective there have to be a substantial number of commuter whose preference ordering goes from 1) Driving over cycling, subsidized Metro to 2) Subsidized cycling over driving, subsidized Metro. I contend that there are few people with such priorities. The likely cyclists are those who are already taking metro, because these people already have relatively short commutes and demonstrate a reluctance to drive.
5) Cycletracks: I’m looking forward to my upcoming rant on comparative cycling facilities. Suffice it say, my preferences are in order: sharrows, same direction bike lanes, multiuse trails and last cycletracks. I find street riding with auto traffic safer than trail riding. Cycletracks are the worst of all worlds: a two way trail in a street. The Custis trail in Rosslyn is a glorified sidewalk. I think you are much safer in the normal traffic lanes on 15th Street and Pennsylvania Ave. The accident reports in this forum tend to bear this out. Road paint associated with on-street bicycle facilities is hardly a big expense and not really a tradeoff when looking at improving infrastructure.
6) CaBi: I don’t have a problem with CaBi if it is not too heavily subsidized. If it is a gateway drug for some future commuters, that’s all to the good. However, CaBi’s TIGER application states that mostly it displaces people walking, taking Metro, and taking cabs. Very little displaces private cars.

[baiskeli]

@DismalScientist 9812 wrote:

But population growth almost implies per capita growth in person miles if all that growth means an expanded developed area (i.e. it is all not increased density). It’s hard to model, but as the developed area grows, the distance between home and some interesting destination for the average person must grow, implying greater travel per person.

Yes, that’s exactly what I’m saying. And that’s why as a city grows, cars and roads become a less sustainable mode of travel. Congestion increases, even if you try to accommodate it with new roads, because each additional person requires even more of a share of road capacity than the person before did. I think your dismal science term for it is “diminishing returns.”

So you have to start to change both the development and the transportation modes that serve it, which go hand in hand of course and feed into each other. If you just keep adding low-density, road-dependent development to meet population growth, you’d end up with suburbs stretching into West Virginia. Those people aren’t going to be able to get around by car any faster even without any congestion, simply because they live too damn far away. They’ll still spend an hour or two on the road every day, doesn’t matter if they are going 60 mph on congestion-free roads.

[WillStewart]

Yes, citations are indeed important, as they help others understand how one came to take a particular position on a subject;

Generated and induced traffic;

1. Todd Litman, Generated Traffic and Induced Travel – Implications for Transport Planning, 8 June 2011, Victoria Transport Policy Institute

Road improvements that reduce travel
costs attract trips from other routes, times and modes, and encourage longer and more
frequent travel. This is called generated traffic, referring to additional vehicle traffic on a
particular road. This consists in part of induced travel, which refers to increased total
vehicle miles travel (VMT) compared with what would otherwise occur (Hills 1996).

Generated traffic reflects the economic “law of demand,” which states that consumption
of a good increases as its price declines. Roadway improvements that alleviate congestion
reduce the generalized cost of driving (i.e., the price), which encourages more vehicle
use. Put another way, most urban roads have latent travel demand, additional peak-period
vehicle trips that will occur if congestion is relieved. In the short-run generated traffic
represents a shift along the demand curve; reduced congestion makes driving cheaper per
mile or kilometer in terms of travel time and vehicle operating costs. Over the long run
induced travel represents an outward shift in the demand curve as transport systems and
land use patterns become more automobile dependent, so people must drive more to
maintain a given level of accessibility to goods, services and activities

2. Patrick DeCorla-Souza, AICP, ACCOUNTING FOR INDUCED TRAVEL IN EVALUATION OF URBAN HIGHWAY EXPANSION, Federal Highway Administration

Induced travel can come from the following sources:

An increase in person trip production (P) related development

An increase in person trip attraction (A) related development

An increase in number of daily motorized person trip P’s and A’s per development unit

An increase in average motorized person trip distance

An increase in share of person travel by private motorized vehicles

A shift in vehicle travel to improved facilities from unimproved facilities within a corridor, or to an improved corridor due to diversion of traffic from other corridors.

When the frame of reference is the regionwide travel market, induced travel comes only from the first five sources. The sixth source comes into play at the facility and corridor levels, and may be more appropriately defined as diverted travel. Most transportation models do not capture induced travel from the first three sources. Most urban modelers do not increase input forecasts of total development regionwide to account for additional business and residential development induced to locate in the region by improvement in transportation levels of service, and often improved corridors are modeled with the same development inputs for the Build and No-Build cases.

[DismalScientist]

@baiskeli 9818 wrote:

Yes, that’s exactly what I’m saying. And that’s why as a city grows, cars and roads become a less sustainable mode of travel. Congestion increases, even if you try to accommodate it with new roads, because each additional person requires even more of a share of road capacity than the person before did. I think your dismal science term for it is “diminishing returns.”

So you have to start to change both the development and the transportation modes that serve it, which go hand in hand of course and feed into each other. If you just keep adding low-density, road-dependent development to meet population growth, you’d end up with suburbs stretching into West Virginia. Those people aren’t going to be able to get around by car any faster even without any congestion, simply because they live too damn far away. They’ll still spend an hour or two on the road every day, doesn’t matter if they are going 60 mph on congestion-free roads.

True enough. Without increasing density, it is difficult to develop transit systems. The problem is that many people do not want to live in dense areas. People don’t want to raise kids in apartments. So there is a tradeoff… Do people want to limit geographic growth and bear the costs of increasing density; do people want to limit population growth in an area, thereby reducing economic opportunity and local asset values and forcing population growth issues to other areas; or do people want let things go on as they are and bear the increased congestion and infrastructure costs? I don’t think there is a political consensus in this area and I think proponent of various positions tend to discount these inherent tradeoffs.

[WillStewart]

What tends to happen over and over again (Til Hazel, Toll Brothers, etc) is that land speculators influence the elections in outer suburbs and exurbia to install development-friendly politicians. These politicians then change land use plans (or grant waivers) so that developers can turn farmland into housing developments. The houses are inexpensive, because the land is inexpensive, and the taxes are initially cheap. When roads, schools, etc have to be built, then taxes go up and residents blame the politicians who come later.

[Author]

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