October 28, 2009
October 20, 2009 2 Comments
From PG: A blogpost by Brad Templeton: Is green U.S. mass transit a big myth?
These studies express transit energy efficiency in terms of BTUs per passenger-mile. The BTU is the English system unit of energy, and it’s equal to 1055 joules. On pure conversion, there are 3413 BTUs in a kw/h. To turn BTUs/mile into miles per gallon, you divide into 125,000, the number of BTUs you get from burning a gallon of gas.
The DoE figures describe the average car as using 5500 BTUs/mile (23mpg) or 3,500 BTUs/passenger mile with an average load of 1.57 passengers. This is a “fuel to wheels” number based on burning the gasoline.
Putting the car at 3,500 I was disturbed to learn that city diesel buses and electric trolley buses are both mildly worse than the car in energy efficiency. Light rail systems are also slightly worse, on average, though it varies a lot from city to city. Commuter rail and subway (heavy rail) trains tend to be a bit better, but not a lot better. (Non-hybrid cars are also better at long haul than they are short haul.)
Templeton is basically right, I have seen this data before, and we make basically the same argument in The Transportation Experience (Chapter 19). (A car with 4 passengers would be much much better, since the metal per person in a car is much less than on transit, of course cars generally have less than 4 persons most of the time).
October 20, 2009
Traffic Congestion and Infant Health: Evidence from E-ZPass by Janet Currie and Reed Walker
This paper provides evidence of the significant negative health externalities of traffic congestion. We exploit the introduction of electronic toll collection, or E-ZPass, which greatly reduced traffic congestion and emissions from motor vehicles in the vicinity of highway toll plazas. Specifically, we compare infants born to mothers living near toll plazas to infants born to mothers living near busy roadways but away from toll plazas with the idea that mothers living away from toll plazas did not experience significant reductions in local traffic congestion. We also examine differences in the health of infants born to the same mother, but who differ in terms of whether or not they were “exposed” to E-ZPass. We find that reductions in traffic congestion generated by E-ZPass reduced the incidence of prematurity and low birth weight among mothers within 2km of a toll plaza by 10.8% and 11.8% respectively. Estimates from mother fixed effects models are very similar. There were no immediate changes in the characteristics of mothers or in housing prices in the vicinity of toll plazas that could explain these changes, and the results are robust to many changes in specification. The results suggest that traffic congestion is a significant contributor to poor health in affected infants. Estimates of the costs of traffic congestion should account for these important health externalities.
October 20, 2009
From SciAm: How to Get More Bicyclists on the Road
To boost urban bicycling, figure out what women want ….
In the U.S., men’s cycling trips surpass women’s by at least 2:1. This ratio stands in marked contrast to cycling in European countries, where urban biking is a way of life and draws about as many women as men–sometimes more. In the Netherlands, where 27 percent of all trips are made by bike, 55 percent of all riders are women. In Germany 12 percent of all trips are on bikes, 49 percent of which are made by women.
October 20, 2009
Saturday, August 22, 2009
CANBERRA, Australia –
Traffic noise could be ruining the sex lives of urban frogs by drowning out the seductive croaks of amorous males, an Australian researcher said Friday.
Another explanation for the dearth of frogs? (see section 3.7, there has been other research on this).
October 13, 2009
Once, you could play record albums (you know, vinyl) while in your car … Highway hi-fi by Chrysler. Of course, you could not use standard LPs, but instead had to use a special 16 2/3 rpm format only from CBS records which played for an hour. Further, these records could only be played in your car. I wonder why this technology did not make it. A later version played standard 45 rpms, which seems more useful, (and could play a stack of 14). This format only lasted a year as well.
October 8, 2009
The Transportationist, his spouse, and his children, welcome Samuel into the family. Arriving early, on October 2, 2009 at 7:58 am at Abbott-Northwestern hospital in Minneapolis, and now safely home with his family.