A simplistic but nonetheless useful infographic below highlights the comparative energy footprints of our most common means of transportation. Can’t beat that bicycle.
[div class=attrib]From One Block of the Grid:[end-div]
Frequent fliers the world over may soon find themselves thanking a physicist named Jason Steffen. Back in 2008 he ran some computer simulations to find a more efficient way for travelers to board an airplane. Recent tests inside a mock cabin interior confirmed Steffen’s model to be both faster for the airline and easier for passengers, and best of all less time spent waiting in the aisle and jostling for overhead bin space.
[div class=attrib]From the New Scientist:[end-div]
The simulations showed that the best way was to board every other row of window seats on one side of the plane, starting from the back, then do the mirror image on the other side. The remaining window seats on the first side would follow, again starting from the back; then their counterparts on the second side; followed by the same procedure with middle seats and lastly aisles (see illustration).
In Steffen’s computer models, the strategy minimized traffic jams in the aisle and allowed multiple people to stow their luggage simultaneously. “It spread people out along the length of the aisle,” Steffen says. “They’d all put their stuff away and get out of the way at the same time.”
Steffen published his model in the Journal of Air Transport Management in 2008, then went back to his “day job” searching for extrasolar planets. He mostly forgot about the plane study until this May, when he received an email from Jon Hotchkiss, the producer of a new TV show called “This vs That.”
“It’s a show that answers the kinds of scientific questions that come up in people’s everyday life,” Hotchkiss says. He wanted to film an episode addressing the question of the best way to board a plane, and wanted Steffen on board as an expert commentator. Steffen jumped at the chance: “I said, hey, someone wants to test my theory? Sure!”
They, along with 72 volunteers and Hollywood extras, spent a day on a mock plane that has been used in movies such as Kill Bill and Miss Congeniality 2.
[div class=attrib]More from theSource here.[end-div]
In 2007 UPS made the headlines by declaring left-hand turns for its army of delivery truck drivers undesirable. Of course, we left-handers have always known that our left or “sinister” side is fatefully less attractive and still branded as unlucky or evil. Chinese culture brands left-handedness as improper as well.
UPS had other motives for poo-pooing left-hand turns. For a company which runs over 95,000 big brown delivery trucks optimizing delivery routes could result in tremendous savings. In fact, careful research showed that the company could reduce its annual delivery routes by 28.5 million miles, save around 3 million gallons of fuel and reduce CO2 emissions by over 30,000 metric tons. And, eliminating or reducing left-hand turns would be safer as well. Of the 2.4 million crashes at intersections in the United States in 2007, most involved left-hand turns, according to the U.S. Federal Highway Administration.
Now urban planners and highway designers in the United States are evaluating the same thing — how to reduce the need for left-hand turns. Drivers in Europe, especially the United Kingdom, will be all too familiar with the roundabout technique for reducing left-handed turns on many A and B roads. Roundabouts have yet to gain significant traction in the United States, so now comes the Diverging Diamond Interchange.
[div class=attrib]From Slate:[end-div]
. . . Left turns are the bane of traffic engineers. Their idea of utopia runs clockwise. (UPS’ routing software famously has drivers turn right whenever possible, to save money and time.) The left-turning vehicle presents not only the aforementioned safety hazard, but a coagulation in the smooth flow of traffic. It’s either a car stopped in an active traffic lane, waiting to turn; or, even worse, it’s cars in a dedicated left-turn lane that, when traffic is heavy enough, requires its own “dedicated signal phase,” lengthening the delay for through traffic as well as cross traffic. And when traffic volumes really increase, as in the junction of two suburban arterials, multiple left-turn lanes are required, costing even more in space and money.
And, increasingly, because of shifting demographics and “lollipop” development patterns, suburban arterials are where the action is: They represent, according to one report, less than 10 percent of the nation’s road mileage, but account for 48 percent of its vehicle-miles traveled.
. . . What can you do when you’ve tinkered all you can with the traffic signals, added as many left-turn lanes as you can, rerouted as much traffic as you can, in areas that have already been built to a sprawling standard? Welcome to the world of the “unconventional intersection,” where left turns are engineered out of existence.
. . . “Grade separation” is the most extreme way to eliminate traffic conflicts. But it’s not only aesthetically unappealing in many environments, it’s expensive. There is, however, a cheaper, less disruptive approach, one that promises its own safety and efficiency gains, that has become recently popular in the United States: the diverging diamond interchange. There’s just one catch: You briefly have to drive the wrong way. But more on that in a bit.
The “DDI” is the brainchild of Gilbert Chlewicki, who first theorized what he called the “criss-cross interchange” as an engineering student at the University of Maryland in 2000.
The DDI is the sort of thing that is easier to visualize than describe (this simulation may help), but here, roughly, is how a DDI built under a highway overpass works: As the eastbound driver approaches the highway interchange (whose lanes run north-south), traffic lanes “criss cross” at a traffic signal. The driver will now find himself on the “left” side of the road, where he can either make an unimpeded left turn onto the highway ramp, or cross over again to the right once he has gone under the highway overpass.
[div class=attrib]More from theSource here.[end-div]
Energy efficiency sounds simple, but it’s rather difficult to measure. Sure when you purchase a shiny, new more energy efficient washing machine compared with your previous model you’re making a personal dent in energy consumption. But, what if in aggregate overall consumption increases because more people want that energy efficient model? In a nutshell, that’s Jevons Paradox, named after a 19th-century British economist, William Jevons. He observed that while the steam engine consumed energy more efficiently from coal, it also stimulated so much economic growth that coal consumption actually increased. Thus, Jevons argued that improvements in fuel efficiency tend to increase, rather than decrease, fuel use.
John Tierney over at the New York Times brings Jevons into the 21st century and discovers that the issues remain the same.
[div class=attrib]From the New York Times:[end-div]
For the sake of a cleaner planet, should Americans wear dirtier clothes?
This is not a simple question, but then, nothing about dirty laundry is simple anymore. We’ve come far since the carefree days of 1996, when Consumer Reports tested some midpriced top-loaders and reported that “any washing machine will get clothes clean.”
In this year’s report, no top-loading machine got top marks for cleaning. The best performers were front-loaders costing on average more than $1,000. Even after adjusting for inflation, that’s still $350 more than the top-loaders of 1996.
What happened to yesterday’s top-loaders? To comply with federal energy-efficiency requirements, manufacturers made changes like reducing the quantity of hot water. The result was a bunch of what Consumer Reports called “washday wash-outs,” which left some clothes “nearly as stained after washing as they were when we put them in.”
Now, you might think that dirtier clothes are a small price to pay to save the planet. Energy-efficiency standards have been embraced by politicians of both parties as one of the easiest ways to combat global warming. Making appliances, cars, buildings and factories more efficient is called the “low-hanging fruit” of strategies to cut greenhouse emissions.
But a growing number of economists say that the environmental benefits of energy efficiency have been oversold. Paradoxically, there could even be more emissions as a result of some improvements in energy efficiency, these economists say.
The problem is known as the energy rebound effect. While there’s no doubt that fuel-efficient cars burn less gasoline per mile, the lower cost at the pump tends to encourage extra driving. There’s also an indirect rebound effect as drivers use the money they save on gasoline to buy other things that produce greenhouse emissions, like new electronic gadgets or vacation trips on fuel-burning planes.
[div class=attrib]Read more here.[end-div]
[div class=attrib]Image courtesy of Wikipedia, Popular Science Monthly / Creative Commons.[end-div]