Thursday, August 28, 2008

Corn Ethanol and Economics

Mark sent in a question about corn ethanol, and I think the best way to respond is with a link to zfacts.com, which I think does the best job of analyzing the data out there to look into the possibilities. They make sure to use the most favorable pro-ethanol assumptions (they also show their work). It's a cop-out, but they do a much better job than I could, so here you go.

Here's the summary:

There's $1.45 of subsidy in every gallon of ethanol. Since ethanol only contains 2/3 of the energy of gasoline, this is equivalent to about $2.20 per gallon of gasoline. These subsidies consist of a blender's credit (which goes to fuel companies that include ethanol in motor vehicle fuel) as well as production subsidies for corn (which goes to farms that produce field corn that is sold to ethanol producers). There is also the artificial price support of the federal ethanol production requirements, which require blenders to use more than the market equilibrium amount of ethanol in fuel.

Ethanol has the strange tendency to sell for the same price or higher per gallon as gasoline, even though it has less energy per gallon. This means that if you fill your tank with E85, you will get poorer fuel economy and have to visit the gas station more often, costing you more.

So we're paying billions in subsidies for fuel that ends up costing the same and burns up faster, while using up valuable farmland as well as the fuels needed to process the corn into ethanol? Smart.

Who gets rich off of this? Owners of corn-producing land for one. Land that can produce a crop that is highly subsidized is worth more after the subsidy than before. Therefore, the owner can charge more for rent if the farmland is leased, and the imputed rent* from a farmer-owner is greater. Because the processing of corn into ethanol has relatively low barriers to entry, the returns to processing should not be higher than normal economic profits. Likewise, since anyone can go to school, learn to farm, purchase equipment, rent land, and farm some corn, the actual farmer should not accrue any unusual profits either**.

*Just look it up, I'm not going to go into imputed rent here
**I'm not saying farming is easy or that "any dummy could do it", I'm saying that there are no particular barriers to entry like patents, regulations or market forces that would prevent a reasonably motivated and capable firm from starting up. Something I learned from "The Undercover Economist" is that scarcity creates profits, and the scarcity when it comes to producing ethanol is productive farmland.

Wednesday, August 27, 2008

Transit Tourism - Santa Cruz, San Jose, San Francisco


IMG_1329
Originally uploaded by infosnackhq
I've got a new photostream of my transit tourism in California here. I haven't used Flickr much yet so I'm still getting the hang of adding descriptions and comments.

Monday, August 25, 2008

Mouseprint.org - Consumer Watchdog

I have a new favorite blog over at mouseprint.org.

They document the fine print in advertising or packaging that completely contradicts what the main text is saying. They also document the slowly shrinking product packaging that manufacturers use to hide inflation.

Ever notice that it's no longer a "half gallon" size ice cream container? It's now 1.75 or even 1.5 quarts. Same price, 25% less product. That's where inflation happens.

They have other hilarious posts where the most creative advertising gimmicks happen. Go check it out.

Back from trip - NYT Olympic Medals Graphic

I'm still recovering from my trip to CA, so all I have to offer this morning is this NYT Graphic depicting medal counts for all the Summer Olympic games of the modern era. Enjoy.

I noticed a couple things:

Communist countries like winning medals and are pretty good at it. Observe the East German and Soviet medal counts during the 60s and 70s. 1980 doesn't count because the US and some other countries boycotted, and neither does 1984 since the Soviet Union and some others boycotted.

The games have become more global since the early days. The number of countries winning medals has gone from less than two dozen in the 1920s and earlier to 87 during the 2008 games. Of course, the number of participating countries has increased since the early days, too.

There is/was a huge homefield advantage, at least in the early days. The first five Olympic games were dominated by the host country, until it was held in Belgium in 1916. Even then, Belgium went from 14th place in 1912 to 5th, and increased its medal count sixfold from 6 to 36.

Wednesday, August 20, 2008

Light Posting this Week

In case you haven't figured it out so far, there will be light posting until Monday because I'm on vacation in California.

When I return, photos and a report from riding the VTA light rail in San Jose, CA, from riding the Market St. Railway in San Francisco, CA, and some smart growth-related photos and commentary from San Jose, Capitola and Santa Cruz, CA.

In the meantime, I'd enjoy hearing from you in the comments. What would you like to hear more about?

Friday, August 15, 2008

CAFE Standards Analysis

Ok, I'm not an expert on the subject by any means, but I did promise that I would look into Corporate Average Fuel Economy standards for the readership.

First, go check out the wikipedia page on the subject. Go ahead, I'll wait. Read it? Good.

My principles for fixing CAFE are:

First, reductions in fuel consumption are cheapest if the reductions can be done by the most efficient corporation, and in any category of production. Therefore, dividing the fleet into domestic and imported vehicles, and into passenger car and light truck categories is less efficient at improving mileage standards than simply lumping all vehicles made by a manufacturer together, and dividing the US fleet of vehicles into separate manufacturers is less efficient than lumping the entire US fleet together. Therefore, as proposed by others, I would like to see the CAFE standards change to be Nationwide Average Fuel Efficiency standards.

Under this system, manufacturers that make vehicles that are highly efficient should be able to sell credits to those that don't quite meet the average. For example, let's say for sake of example that Honda# makes great small cars that are fuel efficient (above the NAFE standard), but are not as profitable per unit as GM's excellent large trucks, that are generally not fuel efficient (below the NAFE standard). Under the current rules, GM is required to either pay a penalty, reduce sales of large trucks, or develop and sell small cars, which are not desired in the market. Additionally, Honda is encouraged to develop and sell large trucks, which are not desired in the market.* Under my proposal, Honda would be able to sell excess NAFE "credits" to GM. GM can concentrate on making great large trucks (while still having an incentive to make them efficient and profitable), and Honda has an incentive to make great small cars (and has an incentive to make them even more efficient. Both companies concentrate on what they do best. It's like the theory of comparative advantage, and the product is efficient vehicles.

Second, the fuel efficiency standards should assume a process of continuous improvement. Once we reached 27.5 MPG as the standard in 1985, we remained there for over two decades (in 2007 an increase in the standard to 35 MPG by 2020 was approved). We should have been increasing the standard by some amount every year for the past two decades. I'm just going to throw a number out there and say 2% per year. During the "active CAFE" period, we doubled efficiency in 10 years, or a 7% compounded improvement. Back then, we had the low hanging fruit (vehicle size reduction, locking automatic transmissions, front wheel drive, fuel injection), but there are certainly additional fruit that can be picked (selective displacement, CVT, reduced rolling resistance tires, advanced materials, efficient streamlining). If we had kept up 2% per year since 1985, our current 2008 efficiency requirement would be 43.5 MPG, and by 2020, it would be 55 mpg. If that growth rate were too high, the federal government could sell additional credits through a "safety valve" provision at a reasonable price**.

Third, the system needs to move from measuring and reporting "miles per gallon" to "gallons per 100 miles", similar to Europe's L/100km. As reported by Duke University, consumers are better able to make informed decisions about reducing fuel usage when presented with gallons per 100 mile figures compared to MPG. An example is comparing improving the efficiency of an SUV from 10 to 15 miles per gallon to a car that improves from 20 to 30 miles per gallon. Sure, both improve by 50% when you go by MPG, but compare gallons per 100 miles and you'll see the difference. The SUV goes from consuming 10 gallons to 6.7, and the car goes from consuming 5 to 3.3. The SUV driver saves 3.3 gallons, and the car drive saves 1.7 gallons, only half as much, even though the improvement in MPG is the same as a percentage of baseline, and is twice as much in absolute (MPG) terms. If the real goal is to reduce gasoline consumption and assuming people want to travel a certain number of miles, reporting gallons per 100 miles is a better way to do it.

Fourth, the EPA fuel efficiency standards and the NHTSA standards need to be merged. The window sticker you see is based on the EPA standard, and CAFE compliance is judged by the NHTSA standards. The differences are not terribly important other than to say that the EPA standard reflects more real-world driving conditions and is generally lower than NHTSA, which is why the window stickers seem lower than the 27.5 MPG standard we're supposed to be getting.

Fifth, the "boost" in reported fuel efficiency for vehicles that can burn 85% ethanol (such as GM's "flex fuel" vehicles) should be scrapped, or at least limited by the ratio of E85 ethanol sold in the US to that of regular gasoline. These vehicles get a boost of about 1 MPG based on ability to burn E85, or 85% ethanol, 15% gasoline. There is no requirement that E85 actually be available or even sold, it's the possibility of burning it that gives manufacturers a pass. Is it any wonder that GM's largest vehicles are "flex fuel", while none of the smaller cars are? None of the flex fuel vehicles get better than 24MPG highway, and most of them are no better than 20MPG highway. On the other hand, GM offers more than a dozen models above 30 MPG highway, and none of them are flex fuel capable, even though the only changes required are minor.

Last, all passenger non-commercial vehicles should fall under the same fuel efficiency standard. Up until recently, vehicles over 6000 lbs gross vehicle weight rating (GVWR) were exempt, leading to such oddities as the 2005 BMW X5, which had a GVWR of 6008 lbs. Since the GVWR is not a real weight (merely representing the theoretical "fully loaded" weight of the vehicle), it's pretty obvious that BMW was trying to avoid complying with the standard. My reform would be that all vehicles would be included in the national average efficiency as long as they did not require a commercial driver's license to operate. Commercial vehicles have a GVWR of more than 26,000 lbs, carry more than 10 passengers, are operated for hire, carry hazardous materials or tow a trailer weighing more than 10,000 lbs. This reform would envelop the International CXT, which gets 8-10 miles per gallon with a 70 gallon tank (costs almost $300 to fill!), and has a GVWR of 25,999 (suspicious, no?) lbs.

All of these reforms together would make CAFE (under my proposal, NAFE) much more flexible for manufacturers, while providing fewer avenues for cheating and increasing consumer understanding. They would also increase efficiency continuously over time. Some of them (#1, partially, #2, as noted above, #5 has been transferred from E85 to Biodiesel, and #6, partially) have been adopted into law, and some are still waiting.

*Again, we're making assumptions here. I'm not trying to disparage Honda's trucks, or GM's small cars.
#Full disclosure: I own about $250 of Honda stock.
** I have no idea how to determine said "reasonable price". It's certainly no less arbitrary than the current $5.50 penalty per 0.1 MPG for not meeting the current CAFE.

Wednesday, August 13, 2008

Interesting analysis of Obama's tax plan

Over at The American, there's this interesting analysis of Obama's tax plan.

Their chart illustrates one of the difficult tradeoffs that politicians have to make when designing tax relief intended for the "middle class" or the poor. These tax relief provisions are typically structured as a credit that "phases out" above a certain income. For example: the "child tax credit" is a $1000 credit per child available to families* making less than $110,000 per year**. Above 110,000 per year, the credit is slowly taken back at a rate of $50 per $1000 that your income exceeds $110,000.

That means that a family that earns $130,000 and has a child pays $1000 more in taxes (in addition to the regular income tax) than a family that earns $110,000 and has a child. Economists call this an increase in the marginal tax rate.*** Higher marginal tax rates have the downside of discouraging people from earning additional income. The American summarized the additional marginal (income) tax rates in the Obama plan in the figure shown at right.

I think this might be a misleading analysis, in that we're only shown a portion of the income scale (what's going on above $125,000 in income, or below $25,000?), and we're not given the total taxes paid at each income (it would be less misleading to publish the "Suits Index" for the change). There's also the problem of selecting your test case to make your intended point strongest. In this case, the selected family has a young child and a college student. Both children make the family eligible for large tax credits that phase out in the income range shown. I also found this statement interesting:
Obama also makes certain credits refundable, which introduces a tax penalty of 10 percent or 15 percent, depending on the income bracket.
It takes a certain leap of logic to imply that a tax credit that has been made refundable (meaning that you can get it even if you don't earn enough to pay any tax) is somehow a "tax penalty". Since the authors are resident scholars at the conservative American Enterprise Institute, I would expect this kind of distortion, as I've seen it before from them.

These provisions are an interesting tradeoff for politicians. The tradeoff is between keeping the total fiscal impact of a provision small, and keeping the marginal rates low and at higher income. For instance, what if the Child Tax Credit was given only to people making less than 20,000 per year, and was completely phased out at $22,000. That means that people trying to decide to work a little harder and earn $22,000 instead of $20,000 would be facing a marginal rate of 50%, and they'd only get $1000 (actually less) of the increase in their income because of the loss of the child tax credit. However, such a credit would not be as large a fiscal impact because far fewer people with children earn less than $20,000 than $110,000 per year.

Now compare the current tax credit with one that phases out between an income of $2 million and $3 million. This tax credit would be quite expensive, because practically everyone earns more than $1 million****, so almost everyone with a qualifying child would have their taxes reduced by $1000^. The marginal tax rate increase is small, only 0.1%, and hits only people making between $1 and $2 million, so the incentives to work have been reduced drastically.

As shown above, it's a tradeoff, between keeping the budget from busting and making sure that there are adequate incentives to work. I think it's good to keep in mind that the high marginal rates in Obama's plan reflect that these represent large tax benefits granted to lower income taxpayers, and that relative to current law, everyone making less than the phase-out income will be paying less in tax than before. Sure, you face a higher marginal tax because the credits are being phased out, but you have more money in your pocket than before, and that's nothing to frown at.

*"married filing jointly" status
**Modified AGI, which usually means total income before deductions
***If you're curious, you can detect when this is happening to you when you do your taxes. Just look for places in the calculation where you're subtracting some amount from your AGI or your taxable income, then multiplying the result by some fraction. In this case, you subtract $110,000 from your AGI, then multiplying the result by 0.05.
****See this chart, footnote (3). 99% of tax filers have less than $620,000 in income.
^Except for those families not earning enough to pay income tax, because the child tax credit is not refundable. For them, there is the "additional child tax credit, which is smaller and not discussed here.

Tuesday, August 12, 2008

My Dad's Birthday

Today is my dad's birthday (Happy Birthday, Dad!). Since he has everything he wants or needs, it's always hard to find something he wants but doesn't know it yet, or needs but doesn't know exists.

So this year, I'm going to give him something that he's probably not expecting. A public note of thanks from his son, and a summary of Dad's best lessons that I remember and have tried to use in my life with a new son of my own.

First, a note of thanks. Dad, thanks for everything. What you taught me, and what you have done for me, they were great gifts. Children can't ever repay their parents, but I hope that I can pay it forward to my kid(s) someday.

Now, Dad's Lessons:

Give back to the community - My dad has always been giving back to the community in some way or another for as long as I can remember. He's currently active in city government, guiding the future development of my hometown. He works with the local Boy Scout troop, helping young men earn their Eagle Scout rank by providing advice and encouragement on their leadership projects. He was in the Navy for at least 30 years, and one of his most rewarding posts must have been when he helped the Kurdish refugees during the Gulf War. I feel a strong need to give back to my community, and I think it was dad's example that taught me that.

Math and Science are really cool. My dad is an engineer, and one thing I remember about growing up was that we were always talking about science or engineering. I didn't realize it at the time, but he would point out interesting bridges, or bring home a drawing from work, and describe how stuff worked. All of this kindled a love for science, math and engineering that has turned into a great major in college, a great job, and a great career (so far!).

Hard Work/Academics are important. I think my dad had high expectations for doing my well in school, but I remember that he was hard at work learning as well, whether it was getting an MBA earlier in his career, or studying to take the PE exam a little later.

Trust Bank Account - He taught me that building up a reputation for honesty and trustworthiness is like building a bank account. It's easy to build up slowly, little by little, making small deposits over a long period of time. It's also easy if you mess up, to make a huge withdrawal and leave your account very low. I've made some mistakes, but this lesson has stuck and reminded me of how important it is to build the account slowly and steadily.

Pay Yourself First - He taught me that in order to have a financially secure retirement, you should make a commitment to invest some of your salary each month, and every time you get a raise, to commit to investing even more. He taught me that it's important to make the investing automatic, so that you don't have to decide every time that you have the money to invest. If you don't get used to having the money, you're less likely to "need" it.

Be Generous - Every one remembers the guy at the table that splits the bill down to the penny. Being an engineer, I would probably have that tendency. But Dad taught me to let go, and chip in a couple extra bucks to smooth things over, even if it's not always quite fair. Because everyone remembers The Guy Who Calculates Everything To The Penny.

Take care of your stuff - Oil changes, washing the car, basic home repair. It's better to buy quality stuff and keep it in good repair, than to have to keep buying stuff that's not worth it in the first place.

Take Advantage of Opportunities - Sometimes you're given the opportunity to go on an African Safari, and it's not clear that you'll ever get the chance again. It's better to just take that opportunity than save the money. You'll regret not going because it's a lot more expensive to go on an African Safari if you're no longer in Africa.

To have a friend, you have to be a friend
- Friendship is a two way street, and it takes effort, at least at first.

Don't keep score - In a close relationship with your spouse, it's not important who's scoring more points as long as you're both trying.

Small Differences Matter - Make sure she opens the jewelry before the kitchen appliances. This one's an inside joke.

I wonder if a tribute blog post is like the 21st century version of the misshapen clay ashtray you make your parents even though they don't smoke.

Monday, August 11, 2008

NYT letter to the editor on 401(k)s or IRAs

The New York Times ran the following letter to the editor:
The biggest problem for many people over 85 is not having enough money to live on. This is especially true of retirees who depend on a 401(k) or an I.R.A. and are now facing inflation, a decline in the stock market and mandatory minimum distributions.

A retirement accumulation that is adequate at age 65 may not be adequate at 85 and will certainly not be at 100. But the mandatory minimum withdrawal schedule forces retirees to withdraw more than they need in their “young” old age, leaving less for their “old” old age, when their medical needs will probably increase.

Surely, it was not Congress’s intention to mandate poverty for the long-lived, most of whom are women. The mandatory minimum withdrawal schedule should be abolished or restructured to allow flexibility for retirees.


401ks and Traditional IRAs are an agreement between you and the US Government. The Government eliminates taxes on a part of your income, and you promise to not withdraw any of that money until you reach at least 59.5 years of age*, and that you promise to withdraw some of your money per year starting at age 70.5. When you withdraw your money, it is taxed as ordinary income. This ensures that the Government eventually receives the tax revenue that was deferred when you earned the original income.

If you eliminate the minimum required distributions, you're backing out of your part of the deal. The government granted a favor by allowing the initial investment to be without income tax, and workers were earning money and making contributions tax-free as early as 1974, when the income tax rates were much higher, including top marginal rates as high as 70%. This was a chance to avoid tax when the top rates are 70%, then pay the tax when the rate has been cut to 34.5%.

Furthermore, by requiring you to take minimum distributions, the government is not forcing you into old-age poverty. The government has no power to force you to spend your money when it comes as a required distribution from an IRA any more than it does to force you to spend your paycheck when you work. When you take your required distributions, if you feel that you will need that money when you are 85, 90, 100 years old, you should put it in an investment account and purchase a mix of stocks, bonds, and cash equivalents that will last you for your retired years. Alternatively, you can open an account at your broker or investment company and purchase nearly the same investments you had before, minus the taxes that have been deferred. You'll be just as wealthy as before, and you'll have received a huge benefit by being able to defer income taxes for decades. Another option would be to purchase a life annuity from an investment or insurance firm, which will guarantee you a certain amount of income for life.

Congress does not "mandate poverty" by requiring minimum distributions, spending the money as soon as you receive it does. By managing the proceeds from minimum distributions wisely, the funds can be extended into very old age. Allowing investors to defer taxes indefinitely into the future only worsens the federal budget deficit, at a time when we are quickly nearing $10T in debt, and have over $45T in unfunded entitlement liabilities, mostly owed to the elderly.

It's only fair that investors that have deferred taxes for decades be asked to pay them on schedule.

*Certain exceptions apply that are not germane to the discussion

Friday, August 8, 2008

Traffic Light at 7th and Virginia, Retimed for Safety


View Larger Map
On my way home from work for the past few years, I've noticed an odd signal behavior going north on 7th Street SE underneath the SE freeway. The intersections with Virginia Ave and I Streets SE are controlled with one traffic light each, but for northbound traffic, it seemed like the two lights were never green at the same time. In fact, just as the northern of the two lights was about to turn yellow and red, the southern light would turn green, allowing just enough time for maybe one or two cars to try to accelerate fast and beat the light. In my opinion, this race caused a hazardous situation, especially with pedestrians trying to cross I Street at the same time. When I have gone through the light during the middle of the day or in the morning, it didn't seem like the light was timed quite the same way. If the lights could somehow be retimed to allow both green at the same time, perhaps drivers would not feel as rushed.

I contacted Tommy Wells (D-Ward 6) through his homepage, who forwarded my question to DDOT. The very next day, I noticed that the traffic pattern was different. When I asked the DDOT employee about it, he stated that the light had its offset adjusted (no phase length change, just the relation to other lights), and offered to meet with me to discuss the signal. I think I may take him up on it today during the day, and I'll post what I find out. There still appears to be an issue with the walk signal across Virginia Ave, in that the north/south green phase was made longer, but the walk phase didn't seem to follow, so I'll make sure to ask him about that.

This was great service from DDOT, and I appreciate the offer to meet and discuss what they did to correct the situation.

Parking Benefit District Case Study - Austin, TX


View Larger Map

San Antonio Street, near the University of Texas, Austin Campus, was a parking nightmare. Without any parking controls, students and commuters would clog the street. Furthermore, the City of Austin has targeted the area for an increase in dense residential development, ensuring that the area's parking woes could get worse.

Enter a little-known program run by the EPA. In 2005, the City of Austin, Texas received a Federal grant under the Mobile Source Outreach Assistance program, a competitive grant run by the EPA to reduce emissions from cars. Under the program, the City received around $20,000 in federal funding to assist with purchasing and installing parking meters under a pilot "Parking Benefit District" program.

The city installed meters along San Antonio Street between Martin Luther King, Jr. Ave (see map), and set up a special fund to ensure the revenue is kept separate from general city funds. Net of expenses for meters and enforcement, all of the revenue is dedicated to the local area. Because the program only recently got off the ground, the revenue is still building up, but once enough has accumulated, "the city will involve stakeholders such as local residents and businesses in determining what kind of streetscape improvements should be funded," said Erica Leak, of the Neighborhood Planning and Zoning Department of the City of Austin. As of this quarter, around $100,000 has been set aside for local neighborhood improvements, which could consist of street trees, better sidewalks, rebuilt curbs and benches.

The parking meters run 5 days a week, from 8am to 5:30pm, and fill up by 10am and remain fairly full during the day, indicating that the $1.00 per hour rate may be set too low. But the rate is the same as in the rest of Austin, and the Parking Benefit District ordinance does not allow for city staff to adjust the rates based on occupancy, as does the Performance Parking Pilot Program (PDF) here in Washington, DC. Instead, to create turnover, there is a two hour parking time limit, and "feeding the meter" is not allowed.

The innovative part of this program over regular old parking meters is the dedicated funding, which is often essential to convincing local stakeholders that installing parking meters is acceptable. For example, the City of Pasadena repeatedly proposed installing parking meters in Old Pasadena to increase turnover and control occupancy, but it was the dedicated funding that brought the business community around. Dr Shoup:
What turned the tide is the city said to the property owners and merchants and residents, "If we put in parking meters, Old Pasadena keeps the revenue for public facilities" and, like that, they changed their attitude and they said, "Let's run the meters until midnight and let's run them on Sunday."
According to Leak, the success of the program is a little too early to tell. "We haven't spent the funds on local improvements yet, so it's too early determine how many improvements can be funded through the program. But as far as promoting parking turnover and reducing a little of the spillover from the UT campus, it's been a success."

The City of Austin is looking into expanding the program to other areas, but no firm plans are made at this time.

Thanks to Erica Leak with the City of Austin for the interview.

My Comment: I think this program indicates that a successful parking program depends on two key elements, the first is demonstrated here where the money is dedicated to local improvements, the other is to set the rates based on occupancy and demand, which is what's done in Redwood City, CA. I'm going to see if I can interview someone there and get their perspective. From Erica's comments, it appears that the parking is very full during the day and that time limits are used to ensure some turnover. With the authority to set rates based on occupancy, the city could have more revenue to improve the community, and they could eliminate the time limits, which are inconvenient at best and at worst are hard to enforce and frustrating for the parker.

Thursday, August 7, 2008

Transit Scheduling

Because I've been busy working on a future post about parking, I'm going to throw up a link before I've even read it:

The Transportation Research Board paper on transit scheduling

Tuesday, August 5, 2008

Lee Highway Streetcar Revisited

In response to a question about ridership on the 3A/3B/3E line, which in some part runs along the same route as a streetcar line that I proposed earlier, WMATA's office of customer relations replies:
For May 2008, the average weekday ridership on Lee Highway Routes 3A, B, and E was 2,752. According to the spring 2006 ride check, the most recent available detailed data by trip and stop, the average weekday ridership between Rosslyn and East Falls Church was approximately 600.
A common metric for determining what transit lines deserve or require an upgrade to higher quality service, such as streetcar, bus rapid transit, or light rail, is called "traffic density", and is measure in passenger-miles (km) per mile (km) of route per day or per year.*  Here's an extensive listing of traffic density for various transit lines.  For example, Houston's new light rail line reported 3.5 million passenger-miles per mile per year, and Boston's green line reports 8.2 million per year for the "B" Boston College line.  Typically, a bus line with a traffic around 5000 per day or 1.5 million per year is a good candidate for upgrade to BRT, or streetcar.  Higher traffic densities such as 20,000 per day or 6 million per year are candidates for grade separated "Heavy Rail" such as a Subway or Metro.

How many passengers are we talking about when we say "5000 per day?"  I think the best way to envision these numbers is to imagine standing next to the route at some average point, and count the number of people in the buses that go by in a single direction in a day.  Assuming a bus line with 6 buses per hour in the peak direction and operation from 6am to 12midnight.  For 5000 per day, that means 40-50 passengers per bus at the average point along the line.  Since transit passengers rarely space themselves out evenly along a transit line, and definitely don't ride evenly throughout the day, I'm going to apply a time peaking factor of 3.0 (based on the WMATA data presented yesterday) and a location peaking factor of 2.0 (made up number - the worst location on the line carries twice as many people as the average) to arrive at a peak loading of 6 times the average, or about 240-300 per vehicle assuming the same 6 buses per hour (10 minute headways).  A 60-foot articulated bus can accomodate 105 passengers, or 70 passengers per 40-foot standard bus.  Therefore, during the peak hour, peak direction we're going to need to increase the number of bus vehicles to 15-20 per hour, which means a bus vehicle every 3-4 minutes.  So for a transit density of 5000 per day, the required service is 10 minute headways off-peak, 3-4 minute headways during peak, for 18 hours a day, all using 60-foot articulated buses.  That's seriously high capacity for a bus, so I can see how that's the threshold for shifting the line to streetcar or light rail service.

Going back to the data reported for the Lee Highway lines (3A, 3B, 3E), WMATA stated that average daily ridership is 2,752 for the whole route or 600 for the route between Rosslyn and East Falls Church.  For that portion of the line, the distance is 6.5 miles.  Even assuming that all 600 passengers per day ride the entire length, that's only 600 per day, which is far below the stated threshold.  I think a future study could be to ask WMATA what the most popular bus lines are and the ridership data (average weekday boardings, average trip length, etc.) for those lines.

*Note that the length units would cancel out and therefore don't matter. However, in order to prevent listing the units as the more cryptic "passengers per day", the length units are sometimes not cancelled.  For brevity I will abbreviate it to millions per year or thousands per day, implying millions of passenger miles per route mile per year or thousands of the same, respectively.

Monday, August 4, 2008

Anatomy of Peak Ridership for WMATA


I recently received some data from WMATA, in the form of the ridership for various half-hour portions of a typical May workday. Due to security concerns, the WMATA contact asked me to report the data only as "peaking factors", which I define as dividing each bin by the maximum bin (see figure at right).

Based on the peak ridership, I decided to look into how many trains per hour WMATA runs to carry the peak load, and compare the change in ridership from the peak to the relative number of trains.


See this figure for the number of trains per hour. Because WMATA does not publish train schedules for peak periods, the data is not perfect, because it was collected by incrementing the departure time in the Ride Guide by 1 minute at a time. The train departure times are apparently not stored internally in any particular order, because though the ride guide reports three different options for travel to your destination, they are not necessarily the next three trains.

Additionally, I was interested in where people were entering the system on the red line. Last year, I obtained data for entries and exits during the morning peak hours, daytime, evening peak and late night, by station and month, for FY 2006 and some of FY 2007. This figure is a summary of red line entries by station for the AM and PM peaks.

Looking at the number of trains per half hour graph, it looks like WMATA runs at least 75% of peak trains between the hours of 7 and 9 in the morning peak, and between 3:30 and 6:30 during the evening peak. These times are also when WMATA ridership is above 60% of peak ridership.

This figure shows passenger entry peak factor divided by train frequency peak factor. This is the best metric I could come up with for estimating how crowded a typical train should "feel". Since the ridership data is based on entries, I use the train peak factor at Grosvenor-Strathmore (20 minutes away from Farragut North) for the time periods before 12 noon, and the data at Farragut North for the afternoon data.

My hypothesis when I started looking into this was that WMATA was probably reducing train service too early in the evening, and should increase the frequency of trains because ridership would justify the additional service. At least for the gross metrics I could determine based on the data I had available for the red line, I have to reject that hypothesis. My metric shows that for the majority of the day during a normal weekday, my "crowding factor" remains close to 1.0 and averages about 0.8, which is desirable because you wouldn't want your trains to spend most of the day during non-rush hour at the same standing load as during rush hour. Not only is that less comfortable, but the riders during the day time are more likely to be able to choose some other form of transportation because the roads are not clogged. If the metric had risen significantly above 1.0 during some off-peak period (indicating that WMATA had decreased the number of trains significantly more than ridership) that would indicate more crowded trains during that period. Fortunately for the riders, it looks like WMATA is doing a good job balancing ridership with available system capacity.

Thanks to a source at WMATA for the data.

Information request from Tesla Motors


Compared to my previous analysis on the topic, Tesla Motors' current vehicle offering has almost unfathomable capabilities. A 220 mile range, 180 watt hours per mile, and a full charge in 3.5 hours means that the battery has to store upwards of 39 kWh ($4.00 worth of electricity), but it has to transfer that energy at 11 kW. As I have previously analyzed, that should require a significantly more powerful electrical connection than the typical wall socket we plug most devices into.

I have put in an information request with Tesla Motors to ask what special equipment is used to charge the vehicle, and what electrical system upgrades they recommend for a homeowner that wants to get the 3.5 hour charge performance listed on their website.

If I hear from them, I'll be sure to write up their answer. Update -- It looks like someone from Tesla Motors may have left the answer in an anonymous comment.

Friday, August 1, 2008

WMATA Lunchtime Chat

I encourage readers to check out WMATA's lunchtime chat happening right now. I submitted a question about Smartrip and passes. We'll see if it gets answered.

My question was not addressed. I think it would be pretty interesting if they just posted the rest of the pending questions at the end.

Arlington County to upgrade Courthouse Parking Lot with New Meters

UPDATE: According to Arlington County, applying the numbers to the pavement is delayed, so the pay-by-space meter start is delayed until next week.

This coming WednesdayNext week (8/11/08), visitors to the Courthouse area of Arlington will have a new way of paying for parking -- at the County's newest multispace meters.

The meters will control parking fees for the middle three aisles of parking spaces at the Courthouse lot, 88 spaces out of over 180. Unlike the other multispace meters already up and running in the Clarendon neighborhood on Clarendon Boulevard and at Virginia Square on Fairfax Drive and N Monroe Street, which print a receipt that is then placed on the dashboard, the Courthouse meters will be a pay-per-space system.

"Basically, you park and look for your space number marked on the pavement. Then, you enter your space number at any of the three kiosks, and make your payment. If you need a receipt, push the green button. There's no need to display a receipt, simply pay and get on your way," said Sarah Stott, Arlington County's parking manager.

The new solar-powered meters are much more advanced than the old "single head" meters, and cost about $8,000 per unit.

The old meters produced little data, other than their operational status, but the advanced meters, also known as "multispace meters" have capabilities that the County should be able to use to improve parking availability.

For example, the new meters are able to report how much parking is being sold at a given time. Armed with this information and backed up with in-person counts, parking management should be able to more accurately determine how crowded on-street parking actually is in different locations, as well as detect changes in parking behavior.

Though a proposal has not been officially approved, the county may be able to use this information in the future to adjust pricing to balance the demand for parking with available on-street space. The old single head meters only allowed gross adjustments, such as the hours of operation, price per hour (constant rate throughout the day), and maximum time limit. The new meters are capable of much more detailed adjustment.

In addition to data collection and variable pricing, the new pay-per-space system is at least compatible with the idea of payment by cell phone, which has been successful in West Palm Beach, FL, Redwood City, CA, and abroad. Parkers would be able to use their cell phones to add time to the parking meter without having to re-visit their cars. Arlington is currently researching the technology, though there is currently no funding for implementation. Pay-by-cell is one of the policy goals mentioned in Arlington County's Master Transportation Plan.

The new meters are currently installed on-site, but are inactive and covered up. Tuesday night Soon, the old meters will be removed and the new ones unveiled and activated. Arlington plans on having two people available on-site from Wednesday to Friday during the week to explain the use of the meters and answer any questions.

The meters at Courthouse, like all meters in Arlington, operate from 8:00 am to 6:00 pm Monday through Saturday. The new meters accept coins (dollar or quarter coins), credit or debit cards. There is a Farmer's Market on Saturday from 8:00 am to 12 noon nearby.

Thanks to Sarah Stott at Arlington County for the interview. Image courtesy Arlington County, used without explicit permission.