Friday, December 30, 2011

Let's Walk!

According to Cole Porter:

. . . birds do it, bees do it, even educated fleas do it, let's do it . . . 

No, not that . . . I mean, let's Walk!

It's good for our health, our neighborhoods, our budgets, our highway department budgets, and our environment. Let's do one more thing: let's make it cool! Take that $100,000 you were planning on laying down on a new set of wheels, and lay it down for a cool new Walk jersey. You'll have a little change left over, so go ahead, buy one for your neighbor! Be the first ones in your neighborhood.

Thursday, November 3, 2011

WMATA's SmarTrip Machines Offer Potential for Loss and Fraud

Here are the instructions from the Washington Metropolitan Transit Authority (WMATA) website for topping up SmarTrip farecards:

"1. Go to a Passes/Farecards machine, located at the entrance of every Metrorail station.

2. Touch your SmarTrip® card to the circular target.

3. Follow the prompts on the screen.

4. Insert a) money or tokens, b) a used farecard or Metrochek valued less than $7 or c) an unused farecard or Metrochek of any value. If you have more than one farecard or Metrochek, each will require a separate transaction. You may also use your Visa, MasterCard, Discover, American Express or ATM card.

5. Press the plus (+) or minus (-) button until the amount displayed is the new value you want your SmarTrip® card to have. The added value cannot be less than the trade-in value of the Metrochek or farecard.

6. Touch the SmarTrip® card to the circular target a final time. This updates the card and shows the new balance."

Here's the problem. One of the prompts in "3. Follow the prompts on the screen" above is "Add Value." We discovered--by accident--that if a first SmarTrip user initiates this top up process but leaves the machine with the "Add Value" prompt on the screen, and a second SmarTrip user arrives, presses "Add Value," inserts money, and then touches the circular target with his or her card, the money remains in the machine but the transaction is cancelled.

Does the money go to the first person's card--a fraud opportunity--or does it simply end up in WMATA's account? We don't know. The good news is that we filled out a fare adjustment form which the station manager signed, and when we called the fare adjustment phone number a week later, were were cheerfully informed that the funds were now available for transfer to our SmarTrip card the next time we went by a Metro Station.

It was clear from discussions with the station manager and the agent on the phone that ours was not an isolated experience. However, as far as these WMATA employees seem to know, nothing is being done to eliminate this problem.

Saturday, August 20, 2011

Meat vs Gas Guzzlers

A sea change in the consumption of beef may be in store for Americans, according to a story by Mark Bittman in the New York Times in 2008 ( Such a change would impact the subject of two public policy discussions and political debates: energy consumption and carbon dioxide emissions. Bittman makes two claims about the energy use and emissions from beef relative to that of driving that are of particular interest.

Citing the National Institute of Livestock and Grassland Science in Japan, one of the Bittman's claims is that the emissions from the production of 2.2 pounds of beef is equivalent to the emissions from driving the average European car 155 miles. Let's see.

Information we have indicates that the average European car emits 140 grams CO2 per kilometer, that there are 453.59 grams of CO2 per pound, that there are .621 miles per kilometer, that the average US auto is driven 10,000 miles per year, has an average miles per gallon of 20, and emits 10,211 pounds CO2 per year (this figure, based on our estimated miles per year and miles per gallon, is lower than the 12,500 pounds CO2 figure provided by EPA).

Using these inputs, we find that driving a European auto 70.5 miles emits as much CO2 as one pound of beef. European autos emit CO2 at a rate of 0.309 pounds per kilometer, 0.497 pounds per mile, and 35.0 pounds per 70.5 miles. US Beef consumption per capita is 87.3 pounds, which results in 3,055 pounds of CO2, which according to this claim is the amount generated by driving a European vehicle 6,150 miles. US vehicles emit over twice as much CO2 per mile as do European vehicles, which means that driving 2,992 miles in a US vehicle generates this same amount of CO2.

We have no reason to doubt this claim. However, as for the impact on climate change of beef consumption versus driving, an important conclusion from these calculations is that total emissions from beef consumption are less than thirty percent of the total emissions from US average vehicle miles traveled (VMT). (This doesn't consider substitute effects, i.e., that people who give up beef will eat something else that generates emissions at some unknown lower rate, and that a reduction in VMT may result in an increased use of an alternate form of transit that likewise generates emissions at some unknown lower rate.)

Citing Gidon Eshel, a geophysicist at the Bard Center, and Pamela A. Martin, an assistant professor of geophysics at the University of Chicago, another of Bittman's claims is that the emissions reduction from a twenty percent reduction in beef consumption is equivalent to the emissions reduction that would be realized from switching from a standard sedan to the ultra-efficient Prius.

Using the estimate calculated above of 3,055 pounds CO2 per capita per year from beef consumption, a twenty percent reduction in beef consumption would reduce emissions by 611 pounds. A Prius gets 48 MPG and emits 4,807 pounds CO2 per year, compared to an Accord which gets 21 MPG (slightly higher than the average) and emits 9,217 pounds CO2 per year, which means switching from an Accord to a Prius would reduce CO2 emissions by 4,410 pounds. Therefore, we think this claim is wrong—one could eliminate all beef consumption and not come anywhere close to reducing the amount of CO2 that would be reduced by switching from a standard to an ultra-efficient vehicle.

Looking at the big picture, how much do we need to reduce our emissions? According to the UN and the World Bank, in 2006 the total US emissions per capita were approximately 42,460 pounds, of which "household" emissions (which includes vehicle emissions) were 20,680 pounds. US emissions were more than four times the global emissions per capita of 9,460 pounds. According to the 2007 report from the Intergovernmental Panel on Climate Change (IPCC), global CO2 emissions need to be reduced from the 2000 level by between 50% and 85% by 2050 in order to keep the average global temperature change at what is considered an acceptable level of between 2.0 and 2.4 degrees Celsius. This means the global per capita figure must fall to one eighth or less the US per capita figure. The US, a carbon intensive nation, would have to reduce its emissions by an astonishing 37,000 pounds or more to reach the global target, though no one expects nor is the US being asked to achieve that level of reduction.

Climate change can't be stopped by just changing our eating habits, by just changing our transportation habits, or by just changing any one other thing—we need to make meaningful changes across the board.
Claim #1: emissions from 2.2 # beef equivalent to 155 Mi Euro driving
Euro Mi155NYT
Beef #2.2NYT
Euro gr CO2 / km140.0Wiki
gr / #453.6Wiki
Mi / km0.621Google
Population 2009 (M)307Census
Beef M # 200926,800USDA
Avg Vehicle Mi / yr10,000
Avg MPG20
Avg CO2 / Vehicle / yr10,211US EPA 10,000 Mi 20 mpg
Avg CO2 / Vehicle / yr12,500US EPA
Euro Mi / Beef #70.5
Euro # CO2 / km0.309
Euro # CO2 / mi0.497
# CO2 / # Beef35.0
Beef / Capita 200987.3
# CO2 Beef / Capita 20093,055
CO2 Euro Vehicle / Beef6,150
US # CO2 / mi1.021
CO2 US Vehicle / Beef2,992
Claim #2: 20% beef reduction equivalent to switch from standard to ultra-efficient vehicles
Beef Reduction0.2
Accord (21 MPG) CO2 / yr9,217
Civic (25 MPG) CO2 / yr7,894
Prius (48 MPG) CO2 / yr4,807
Reduced # CO2 at 20% less beef611
# CO2 Accord - Prius4410
# CO2 Civic - Prius3087

- Stuart M. Whitaker

Sunday, August 7, 2011

Transportation Requirements: Reliability

One requirement of any transportation system is that it be reliable--absent reliability, people on inflexible schedules who have a choice of transportation mode won't choose public transit. In order to test the reliability of public transit in northern Virginia, we used an Apple iPhone with GPS enabled to capture (see photos below) the arrival times on four randomly selected stops served by the Fairfax Connector.

How reliable is public transport in Northern Virginia? In our sample, the best arrival was one minute late, the worst was 11 minutes late, with a seven minute average. When routing passengers with connections, the local transit Route Planner builds in five minutes between arrival of one segment and departure of the next segment, which means with this seven minute average delay, most connections would be missed. While this sample size is too small to give any confidence in the level of system reliability, a seven minute delay is a cautionary indicator that calls for closer examination.

Date.time (yymmdd.hhmm)LatLongStopScheduledRouteLate?
110805.113338.9165, -77.220667Tysons Corner Shopping Center11:32FC4021
38.895667, -77.225
Gallows Rd & Elm Pl20:54FC4018
38.916333, -77.221333
Tysons Corner Shopping Center20:59FC4018
110806.223338.914333, -77.221667Tysons Corner Shopping Center20:22FC40211

- Stuart M. Whitaker

Thursday, July 21, 2011

TAI: WMATA Rail, Northern Virginia, Rush Hour

As anyone knows who has been to Tysons Corner recently, there is a massive rail construction project underway to bring rail through Tysons and half way to Dulles Airport. Scheduled for completion in 2013, the future-station locations are terribly served today (not that many people want to visit ground zero of such a construction site, of course!). (More below.)

View TAI: WMATA Rush Hour (Example) in a larger map

Map Key: Click on "View in a larger map."

This map illustrates the transit accessibility of certain locations in Northern Virginia served by WMATA during rush hour (8:00 AM and 5:00 PM). The four Tysons locations are served by bus today but will be served by rail in 2013. The Crystal City location is served by the Blue and Yellow lines today. The other lines are served by the Orange line.

This map also illustrates the extreme difference in the accessibility of different locations. Rosslyn and Crystal City locations are the most accessible, earning Silver Flags, because traveling to these locations by public transit is just as fast as by private vehicle (and without the downtown parking!). The four Red Triangles at the site of future Tyson rail stations illustrate how inaccessible Tysons is today. The other stops on the Orange line are all relatively accessible by transit.

- Stuart M. Whitaker

Wednesday, July 13, 2011

TAI: Panera Bread near 22102, Weekday Morning

The food may be the same, but not all Panera's are! If your looking for Panera's, why not consider accessibility? (More below.)

View Green Your Being: Panera, Northern Virginia in a larger map

Map Key: Click on "View in a larger map."

This illustrates the transit accessibility of four Panera Bread stores at 8:00 AM on a weekday.

Because of transportation patterns peculiar to individual locations--the inability to walk short distances because of barricades and local hazards, the placement of transit hubs, and the design of roadways--locations that are in close proximity to each other may have significantly different TAI scores. This example illustrates the relative accessibility of four Panera Bread stores close to or in Tysons Corner in Northern Virginia. Note that two of the stores, Panera, Tysons Corner, and Panera, Pike 7 Plaza, are located less than a mile apart as the crow flies. However, the store located in Tysons Corner mall (yellow teardrop) has a TAI score of 1.9, half the 3.8 score of the store on Leesburg Pike (red triangle).

- Stuart M. Whitaker

Saturday, April 9, 2011

TAI: Northern Virginia, Rush Hour (Example)

Want to help finding places you can get to via rush hour using transit? Here is one of our earliest demonstrations of the wide variance in accessibility that exists. (More below.)

View Green Your Being in a larger map

Map Key: Click on "View in a larger map."

This map offers an example of the differences in transit accessibility in Northern Virginia (NoVa) during rush hour, 8:00 AM and 5:00 PM.

The most accessible location shown is located at or near the Rosslyn WMATA rail station. During rush hour, the Transit Accessibility Index (TAI) is 1.0, meaning that one can expect to travel two and from this location by public transit in the same amount of time as by private vehicle. Venues within the blue circle, within 0.9 miles of the station, have a TAI of 1.5.

While transit accessibility around WMATA rail stations is always good, locations served by buses may have good accessibility scores as well. The bus terminus at Tysons Corner Shopping Center produces a TAI of 1.9.

While the Arlington County DHS is also served by buses, it isn't a terminus, and as a result, its TAI score is 2.2.

The least accessible location in illustration is the Hilton Springfield, with a TAI of 2.5.

- Stuart M. Whitaker