This article, written by Todd Litman and published on Planetizen, broaches the possibility that the Texas Transportation Institute’s methodology for their annual Urban Mobility Report is flawed by using unrealistic expectations as a benchmark for measuring the cost of congestion. He suggests that a more realistic measurement of cost could be derived by using a congestion benchmark other than a grade “A” level of service (free-flowing traffic), instead using a benchmark of grades “D” or “C” (equivalent to a moderate level of congestion). This is similar to how Metro determines whether a particular roadway is adequate for its modeling of Region 2040 traffic levels, because they do not define the goal for all roadways as “free-flowing traffic,” instead choosing to acknowledge that a certain level of congestion is to be expected in a region with a healthy economy.
Additionally, Todd covers how other issues factor into the measurement of overall cost including providing parking, vehicular accidents, pollution, roadway maintenance, and even the cost of vehicle ownership.
Via Planetizen:
The newest Texas Transportation Institute Urban Mobility Report was recently released, stimulating discussion of congestion costs and potential solutions. Here are some things you should know when evaluating these issues.
There are many several possible ways to measure congestion costs. The method used by the Texas Transportation Institute leads to relatively high cost values, since it assumes that “optimal” roadway conditions are freeflow (level-of-service A), although many transportation economists consider this assumption is inappropriate (see for example, the 2006 report, Costs of Non-Recurrent Congestion in Canada). They argue that congestion costs should be calculated above an optimal threshold, such as level-of-service C or D, which leads to significantly lower cost estimates.
Continue reading “Comprehensive Evaluation of Congestion Costs and Solutions”
10 responses to “Comprehensive Evaluation of Congestion Costs and Solutions”
Similar discussion of the TTI report on Cyburbia at http://www.cyburbia.org/forums/showthread.php?t=31362
From the thread:
“In general they’re focused solely on _mobility_ without consideration of _accessibility._ In the authors’ assumptions, a trip of 2 miles on mass transit is of far less value than a trip of 20 miles by car. They see the ability to drive farther distances at a higher rate of speed as a good thing. They fail to make the connection between land use patterns, the ability to select non-automotive transportation, and per capita VMT.”
Why do these studies appear to me to be
intentionally
made WAY MORE COMPLICATED then necessary?
Of course congestion will get worse as Portland increases density because
DENSITY IS A CAUSE OF CONGESTION
see: DebunkingPortland.com/Smart/TriMet-Hovee.htm
Thanks
JK
DENSITY IS A CAUSE OF CONGESTION
From several hundred years of history of continual urban growth throughout the world, it also appears to be a primary source of economic prosperity. If you want to argue that cities are the source of evil and shouldn’t exist, fine. But lets get real.
“it also appears to be a primary source of economic prosperity.”
Yea but is economic prosperity the only thing that mankind was created for?
IS THAT THE ONLY INDICATOR FOR MANKIND?
Economic prosperity, is that all there is?
“Try not to become a man of success but rather to become a man of value.”
Albert Einstein
Ross Williams Says: From several hundred years of history of continual urban growth throughout the world, it also appears to be a primary source of economic prosperity.
JK: NO! It is not congestion that has been a primary source of economic prosperity, it is having a lot of people close together. Congestion is an undesired side effect (unless you are a clueless planner). As communications improve, that closeness can be achieved without so much physical closeness as we are starting to see with people in various counties working together over the internet.
Ross Williams Says: If you want to argue that cities are the source of evil and shouldn’t exist, fine. But lets get real.
JK: I think the natural evolution is now (and has been for close to 100 years) away from dense cities because people don’t generally like to live in high density and most people no longer have to, although some choose to. Most jobs are now in the burbs as is most shopping and recreation. Low cost travel by automobile and telecommunications have driven this trend and will continue as the cost of both driving and telecommunications ultimately falls while the cost of transit and density continues to increase. I would that dense central cities are obsolete – look at Portland’s core: Dominated by government and a few key businesses. More importantly, it depends of financial support from the rest of the city to survive, even though it is irrelevant to most of the rest of the city.
Thanks
JK
Yea but is economic prosperity the only thing that mankind was created for?
There is nothing that forces people to live in large cities.
It is not congestion that has been a primary source of economic prosperity
Of course not, “it” is density. Sorry for the confusion.
I think the natural evolution is now (and has been for close to 100 years) away from dense cities
But, in fact, that isn’t true. People are continuing to move to cities and small towns and rural landscapes are emptying out. Not only in the United States, but around the world.
Most jobs are now in the burbs
Suburbs are just dense urban developments close to even denser large cities. And if you think suburbs lack congestion, you need to get around the region more.
“There is nothing that forces people to live in large cities”
There are jobs.
“Of course not, ‘it’ is density. Sorry for the confusion.”
You have not made a correlation for the existence between economic growth and density. Density is an effect of economic growth, not it’s cause. Houston, a city less dense than Portland, produces far more than Portland.
“But, in fact, that isn’t true. People are continuing to move to cities and small towns and rural landscapes are emptying out. Not only in the United States, but around the world.”
Arguably, from an anthropological perspective people are social creatures. Yet, they are also not evolved to live in dense surroundings. I remember reading a report, I forget where, that showed that people who lived in highly denser cities were much more neurotic than people living in less dense areas. The choice to live in higher dense areas are, again, jobs (this is not to say that there are not other reasons, but the only way that cities develop is, again, jobs).
“Suburbs are […] dense urban developments…”
I think that the primary argument Mr. Karlok was making is that less dense is better (meaning that a suburb is preferable to a city–their density relative to a city is better).
There are jobs.
You have not made a correlation for the existence between economic growth and density.
I think you did above. There are jobs.
I think that the primary argument Mr. Karlok was making is that less dense is better (meaning that a suburb is preferable to a city–their density relative to a city is better).
Preferable is a value judgment and if you look at the marketplace it is the most densely developed areas that have the most expensive real estate, presumably because people and businesses prefer them. Or, more to the point, they are dense because people prefer them.
[Moderator: Edited for greater indentation/quoting clarity. – B.R.]
I think there may be a bit of miscommunication here. I understood your comment about density to be that because it is dense, there are more jobs. I was stating that density is a result of there being more jobs; I was creating a causal relationship between jobs and density–that jobs creates density, not the other way around.
Your earlier statement suggested to me that you thought that density was the cause of jobs. My point was that this was untrue as Houston, having less density, should, according to your posit, have fewer jobs than Portland. It does not.
Did I understand you correctly? If not, then disregard my post.
In addition, the high value of property is a valuation, as you said, of certain properties. They are highly valued because people with wealthier means values them higher than others. Which I would posit, is why in central cities there are primarily only high-end condos and no middle condos for working class families: there is insufficient demand for them. [Though I could be wrong].
Similarly, there is are also high prices in places like Happy Valley, and wealthier areas in SouthEast Portland. They are very low density (having seen them with my own eyes, traveling). So, the value of property is not an indicator of high demand amongst people to live somewhere, but rather a set crowd of people to live somewhere. As I need not remind you, I’m sure, that it has only been in the last twenty to thirty years that persons of high means considered living in inner cities (specifically downtowns, and extent neighborhoods). I recall you to terms like, “urban blight,” “white flight,” and so forth. Density in many areas decreased, even as jobs grew. Take Detroit, between 1950 and 1960 there was a net decline in population, yet at the same time jobs had yet to leave the area–density was decreasing as jobs increased.