Month: May 2010

How do Roads Spread AIDS in Africa? A Critique of the Received Policy Wisdom

| David Levinson

Interesting study (the downsides of accessibility):

How do Roads Spread AIDS in Africa? A Critique of the Received Policy Wisdom
Date: 2009-11
By: Djemaï, Elodie
This paper empirically analyzes the influence of road proximity on HIV-infection using geographical data on road infrastructure and the Demographic and Health Surveys collected in six African countries. Firstly we show that living in proximity to a major road increases the individual risk of infection. This observed relationship is found to be sensitive to the use of the road and to be robust after correcting for potential selection bias related to the non random placement of people. Secondly, our findings reveal that road infrastructure improves the level of HIV/AIDS-knowledge and facilitates access to condoms, providing no support to the hypothesis that HIV-infection is purely due to ignorance and misfortune. Thirdly, we find that the increased risk of infection is driven by a higher likelihood of engaging in casual sexual partnerships that more than offsets the effect of the increased use of condoms.
Keywords: HIV/AIDS epidemic, spatial inequalities, risk taking
JEL: I10

Archive Gallery: Cities of the Future

| David Levinson

Via David Brin, Popular Science has an Archive Gallery: Cities of the Future which shows the future of cities through the eyes of the techno-optimists of Popular Science magazine. While none have come to pass exactly, in a sense, they are almost all here, examples below. This reinforces the William Gibson quote “The future is already here – it is just unevenly distributed. ” …
Image 1: Exurbia
Image 2: Paris: La Defense
Image 3: Urban Highways
Image 4: Underground City Montreal
Image 5: Elevated Urban Highways (again)
Image 6: Brasilia
Image 7: International Space Station
Image 8: Biosphere (okay, we don’t really have domed cities)
Image 9: Mars (okay, we don’t really have a Mars colony yet)
Image 10: Masdar

Electric Car Bills on the Hill: 10 Things You Should Know

| David Levinson

From earth2tech: Electric Car Bills on the Hill: 10 Things You Should Know

The Electric Drive Vehicle Deployment Act of 2010, introduced in Congress this week, has a simple goal to electrify half of all cars and trucks on U.S. roads by 2030, and a basic strategy: focus the might of the federal government on a small number of pilot communities around the country, subsidizing the buildout of charging infrastructure and purchase of electric vehicles.

Generally, electrification is a good idea (as opposed to fossil fuels) as it is easier to control the environmental effects of energy production if they are at single points. It also enables more easily switching between fuels without having to modify 200 m vehicles, that is it is a more general technology. However, half the cars by 2030 seems singularly unambitious, how about half of all new cars by 2020 being electric, fuel cell, or hybrid, and almost all new cars by 2030?

Battery innovators: The Senate version proposes $1.5 billion for research aimed at delivering a battery that can go 500 miles on a single charge. The Senate also proposes establishing a $10 million prize for whoever delivers a commercially viable battery with those specs.

Somehow I think the $10 million prize will have a greater return on investment than the $1.5 billion in federal research. How about upping the prize (or establishing many prizes) and let the market fund the research with the hope of payoff.

High-speed rail saves time, but price gives pause

| David Levinson

From Global Times in China (via XC) High-speed rail saves time, but price gives pause

“High-speed rails are actually making losses right now,” said Sun Zhang, a professor with the Urban Rail & Railway Engineering Department of Shanghai-based Tongji University. “The high ticket price is surely a reason for the loss. At present, most Chinese people want to save money rather than save time.”
High-speed railway should learn from airlines and offer discounts during periods of lower ridership and to those who place early orders, said Mao Shoulong , a professor at Renmin University of China.

The quest to design a better stop sign

| David Levinson

Tom Vanderbilt in Slate Magazine writes about The quest to design a better stop sign.

[T]rying to improve driver behavior through better signage is as futile as fighting illiteracy with better fonts.

Engineers really need to learn about risk compensation.
Not all safety improvements are futile, but there is a response, so drivers who are protected use some of the safety improvement to behave in a riskier way, as in the video below. This does not imply they necessarily die.

Traffic Paint Shortage Threatens Roadwork: FTA Commissioner Advocates Paint

| David Levinson

The NY Times says: Traffic Paint Shortage Threatens Roadwork

The scarcity stems in large part from the shortage of an obscure chemical compound called methyl methacrylate, one of the key ingredients in roadworthy paint, which must be sturdy, long-lasting and reflective. A major producer of the compound, Dow Construction Chemicals, had production problems this year at a plant in Deer Park, Tex.

I hope this does not set back the plans of FTA … Peter Rogoff, who recently said

Supporters of public transit must be willing to share some simple truths that folks don’t want to hear. One is this — Paint is cheap, rails systems are extremely expensive.
Yes, transit riders often want to go by rail. But it turns out you can entice even diehard rail riders onto a bus, if you call it a “special” bus and just paint it a different color than the rest of the fleet.
Once you’ve got special buses, it turns out that busways are cheap. Take that paint can and paint a designated bus lane on the street system. Throw in signal preemption, and you can move a lot of people at very little cost compared to rail.

IBM’s Patent-Pending Traffic Lights Stop Car Engines

| David Levinson

From Slashdot: IBM’s Patent-Pending Traffic Lights Stop Car Engines

“I’m sorry Dave, I’m afraid I can’t let your engine idle. The USPTO has just published IBM’s patent application for a ‘System and Method for Controlling Vehicle Engine Running State at Busy Intersections for Increased Fuel Consumption Efficiency.’ Here’s how Big Blue explains the invention: ‘The present disclosure is directed to a method for managing engines in response to a traffic signal. The method may comprise establishing communications with participating vehicles; responding to a stop status indicated by the traffic signal, further comprising: receiving a position data from each participating vehicles; determining a queue of participating vehicles stopped at the traffic signal; determining a remaining duration of the stop status; sending a stop-engine notification to the list of participating vehicles stopped at the traffic signal when the remaining duration is greater than a threshold of time; responding to a proceed status indicated by the traffic signal, further comprising: sending a start-engine notification to a first vehicle in the queue; calculating an optimal time for an engine of a second vehicle in the queue to start; and sending the start-engine notification to the second vehicle at the optimal time.’ IBM notes that ‘traffic signals may include, but are not limited to, traffic lights at intersections, railway crossing signals, or other devices for indicating correct moments to stop and to proceed.'”

As the first commenter says “What could possibly go wrong”.
When will people realize serious Vehicle Infrastructure Integration is essentially doomed from the start? There is no deployment path. We can have smart cars on dumb roads (or as in rail, dumb trains on smart tracks), but trying to do both is asking for failure, the coordination problems are just too deep. The environment could perhaps be more informative, but unless it is informative almost everywhere, it will not be of much use.
I will go on a limb and suggest that in the long run, at all but the most congested intersections we’d be better off with smart cars and no electronic intersection controls (i.e even dumber roads), cars which just detected their environment and navigated appropriately. This can be achieved with roundabouts and similar devices.

Fundamentals of Transportation – Featured Book

| David Levinson

In August, 31 of last year I wrote:

As part of the NSF-funded STREET project, we have been putting together ”Fundamentals of Transportation”, a wikibook. I intend to use this next semester as the main text for my Introduction to Transportation Engineering course (CE 3201). We welcome comments and, since this is a wikibook, additions and edits. (Please login using your real name).
This book is aimed at undergraduate civil engineering students, though the material may provide a useful review for practitioners and graduate students in transportation. Typically, this would be for an Introduction to Transportation course, which might be taken by most students in their sophomore or junior year. Often this is the first engineering course students take, which requires a switch in thinking from simply solving given problems to formulating the problem mathematically before solving it, i.e. from straight-forward calculation often found in undergraduate Calculus to vaguer word problems more reflective of the real world.

Well, we are pleased to announce that Fundamentals of Transportation has now been recognized as a “Featured Book” on Wikibooks*. The book is by no means “complete”; but it is I think workable for its purpose, and again any constructive contributions (sections, chapters, new topics, new examples, new problems, better explanations) would still be welcome.
For those of you not familiar with Wikibooks, they operate using the same software and syntax as Wikipedia, and are editable by anyone, though only approved edits are visible. The nature of the project is the creation of textbooks and other references, rather than an encyclopedia, so each project retains its own point-of-view.
* other recent promotions include The Muggles Guide to Harry Potter and Small Numbers