Day: 2012-11-30

Getting from here to there: Bridge Collapse Causes Train Wreck

| David Levinson

David King on Bridge Collapse Causes Train Wreck:

“A train derailed in New Jersey after the bridge it was crossing collapsed. Here is a CNN story. At this point no one knows if the bridge collapse was the cause of the derailment (or was there something with the train that caused the collapse), but will this event serve as a reminder than we tolerate catastrophic failures of our infrastructure far more commonly than most people think? I am not confident that knowledge of potential failure will spur action, nor am I very confident that actual failure will change priorities to fix our infrastructure first. It seems most likely that we will continue to tolerate occasional failure even though everybody knows this is the wrong  way to go about things. Collective action problems are hard.“

Traffic-Related Air Pollution, Particulate Matter, and Autism

| David Levinson

Volk et al (2012) Traffic-Related Air Pollution, Particulate Matter, and AutismAir Pollution, Particulate Matter, and Autism:

“Context  Autism is a heterogeneous disorder with genetic and environmental factors likely contributing to its origins. Examination of hazardous pollutants has suggested the importance of air toxics in the etiology of autism, yet little research has examined its association with local levels of air pollution using residence-specific exposure assignments.
Objective  To examine the relationship between traffic-related air pollution, air quality, and autism.
Design  This population-based case-control study includes data obtained from children with autism and control children with typical development who were enrolled in the Childhood Autism Risks from Genetics and the Environment study in California. The mother’s address from the birth certificate and addresses reported from a residential history questionnaire were used to estimate exposure for each trimester of pregnancy and first year of life. Traffic-related air pollution was assigned to each location using a line-source air-quality dispersion model. Regional air pollutant measures were based on the Environmental Protection Agency’s Air Quality System data. Logistic regression models compared estimated and measured pollutant levels for children with autism and for control children with typical development.
Setting  Case-control study from California.
Participants  A total of 279 children with autism and a total of 245 control children with typical development.
Main Outcome Measures  Crude and multivariable adjusted odds ratios (AORs) for autism.
Results  Children with autism were more likely to live at residences that had the highest quartile of exposure to traffic-related air pollution, during gestation (AOR, 1.98 [95% CI, 1.20-3.31]) and during the first year of life (AOR, 3.10 [95% CI, 1.76-5.57]), compared with control children. Regional exposure measures of nitrogen dioxide and particulate matter less than 2.5 and 10 μm in diameter (PM2.5 and PM10) were also associated with autism during gestation (exposure to nitrogen dioxide: AOR, 1.81 [95% CI, 1.37-3.09]; exposure to PM2.5: AOR, 2.08 [95% CI, 1.93-2.25]; exposure to PM10: AOR, 2.17 [95% CI, 1.49-3.16) and during the first year of life (exposure to nitrogen dioxide: AOR, 2.06 [95% CI, 1.37-3.09]; exposure to PM2.5: AOR, 2.12 [95% CI, 1.45-3.10]; exposure to PM10: AOR, 2.14 [95% CI, 1.46-3.12]). All regional pollutant estimates were scaled to twice the standard deviation of the distribution for all pregnancy estimates.
Conclusions  Exposure to traffic-related air pollution, nitrogen dioxide, PM2.5, and PM10 during pregnancy and during the first year of life was associated with autism. Further epidemiological and toxicological examinations of likely biological pathways will help determine whether these associations are causal.”

In general pollution has been going down in the US, and autism diagnosis has been going up. Some of that may be diagnosis issues (though the previously linked article suggests not). However, there is an interesting point, in the Volk article: “In addition, ultrafine particles (PM0.1) may penetrate cellular membranes.” As we filter larger and larger pollutants from the tailpipe, we may be making more small pollutants (One way to reduce measurable pollution particles is to make them smaller, so they are no longer measured). For instance the as wikipedia says about the Diesel Particulate Filter “maintenance free DPF break larger particles into smaller ones.”

Prediction: D.C. Area Highway and Transit Crowding Will Get Worse

| David Levinson

WAMU reports @ Transportation Nation: Prediction: D.C. Area Highway and Transit Crowding Will Get Worse : ”

The Washington metropolitan region faces worsening traffic congestion and transit crowding as its population and job growth expand over the next three decades, according to a forecast released on Wednesday by a regional planning group.”

Another scare forecast from another Metropolitan Planning Organization. In general when reading these studies:
1. Will behavior not change in response to anything?
2. Will technology not change?
3. Will policy not change?
(On the positive side, they do use a 45-minute cumulative opportunity accessibility measure for transit).

Why does the Institute of Transportation Engineers exist? 10 Ideas for Big Changes – Mike on Traffic

| David Levinson

Mike Spack vs. ITE: Why does the Institute of Transportation Engineers exist? 10 Ideas for Big Changes. See his post for the list.

I am disappointed Mike took down his spreadsheet, though I understand why. If he were at a University, they wouldn’t dare. Frankly, the ITE trip generation data is mostly like a telephone book and can’t be copyrighted, though its specific presentation (and maybe the regressions, though those seem pretty damn uncreative to me) can be. An analysis of that data is certainly fair game. An alternative though would be to set up a Trip Generation Wiki or Google Docs which is open, letting people upload their own data and updating the regressions automatically (since it is a pretty trivial spreadsheet operation).
I am thinking of unjoining ITE, my last professional organization (I quit APA a long time ago due to their profit-maximizing behavior since I gained nothing from the organization and they wanted a non-trivial share of my salary) over their heavy-handed, anti-public, guild-like behavior. If Mike were President, I would reconsider. The backwardness of ITE is one of many reasons Traffic Engineers are becoming increasingly unpopular.