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Is the El a waste of energy?
In a recent Straight Dope column about whether
mass transit wastes energy, you said "transit currently offers no energy
advantage over cars except in the handful of cities with heavy rail and
not all of those. (Chicago's an outlier.)" Are you saying that, despite
all those people crowding onto the trains, the El has no
energy advantage over cars? How can that be?
Eh, maybe I overstated matters when I said the El was an outlier. But it's definitely at the far end of the scale. In fact, the El has the second-worst energy efficiency of major U.S. rapid transit systems. For anyone who's ever shouldered their way onto the Red Line, that may be hard to believe. How can packing ninety people into a box not be more efficient than one guy driving an SUV? Well, it is more efficient, but way less than you'd think. Who or what's to blame for that? Partly the laws of physics. However, a better target in my opinion is Evanston. Folks, not to put you on the spot. But for the sake of the planet, some sacrifices need to be made.
We'll get to that. First the big picture. Here's how the El compares to other U.S. rapid transit systems in terms of energy efficiency:
The El, in short, uses twice as much energy per passenger mile as the rail systems in New York and Atlanta. To give you an idea what that means, energy consumption for a car with an average number of occupants is 3,500 BTUs/mile, according to the U.S. Dept. of Energy. As a practical matter, that means if you have at least one passenger, driving uses less energy on average than taking the El.
Why the poor showing? Some will say: because the CTA is run by bozos! Now, now. I spent some time with CTA management trying to figure what was up. Among the explanations offered: (1) in contrast to other cities, the El runs mostly above ground in a cold climate and costs more to heat; (2) the stations are close together, and speeding up and slowing down consumes energy; (3) the El uses old DC motor technology, not more efficient AC motors.
I'm sure all these things contribute. However, having done some noodling with the numbers, I'd say there's a simpler explanation so simple it sounds almost ridiculous.
It's the size of the CTA's rail cars. They're the smallest of any major transit agency. A fully-loaded El car holds about 90 people. A typical New York subway car can hold, on average, 243 170 percent more, although it's just 90 percent heavier. The more people you can pack onto a rail car, the greater the efficiency. Fact is, the CTA carries fewer riders per car each day than any other major agency in the country:
Why doesn't the CTA buy bigger cars? It can't. Only small cars can negotiate the system's tight curves, especially in the Loop.
But my guess is these changes will produce only modest improvement. Additional increases in energy efficiency will have to come from better management in particular, doing something about the parts of the El that are an energy sink. That brings us to the delicate subject of Evanston.
Here's a chart ranking the CTA's rail lines by a measure of efficiency called the Y Score. The score doesn't indicate energy efficiency, exactly. Rather, it measures how effectively a line makes use of basic rail resources tracks and rolling stock. As you can see, El service shows considerable variation:
Is the Y Score a well-known industry standard? Uh, no. I made it up myself. Y stands for "why are we doing this?" a question, frankly, that needs to be asked. The high-scoring lines, the heart of the system, are an important urban asset. But others are pretty clearly are a waste.
Its amateur origins notwithstanding, the Y Score accords reasonably well with common sense. The Red Line scores highest, and the Brown Line does well too both move a lot of people. The Blue and Orange lines trail distantly, which is perhaps surprising in the case of the former; the O'Hare branch is busy. However, the west side branch out to Forest Park is thinly traveled, and that pulls down the score. The lightly-used Pink and Green lines are a notch lower still, and one occasionally hears suggestions that one or both be closed. But that's never been politically palatable, and I'm not going there now.
Instead, let's talk about the Purple and Yellow lines. Setting aside city boardings on the Purple Line Express, ridership on these routes is pathetically low. More people board at Chicago Avenue on the Red Line (13,000) than at all Evanston and Skokie stations combined (12,000). Granted, running the Yellow Line takes only a handful of rail cars, so it's not a big drain on resources. But the Purple Line is due for major rehab. The CTA has enough trouble finding money to fix up the heavily used parts of the system. Why waste energy, literally and figuratively, on a marginal operation hardly anybody rides?
The only local stops on the Purple Line with significant traffic are Davis Street and to a lesser extent Main Street and they're both a short distance from Metra commuter stations. You can make an argument that the Purple Line ought to be eliminated altogether. If that's too radical, the simplest solution would be setting up a Howard-Main-Davis shuttle, and closing the other stops.
Whatever happens in Evanston, it's hard to imagine any justification for continuing the Purple Line Express in its current form. These trains travel between Howard and Belmont half empty, then fill up from Belmont south. In other words, they're reasonably full for maybe five miles out of a 30-mile round trip. Also, let's face it, as expresses go this one is pretty useless rocketing nonstop for the first half of the journey, then poking along behind Brown Line trains for the remainder. Surely a less wasteful approach would be longer Red Line trains, or better yet, a proper north side express service that would save energy and shorten travel times. (Yes, I have some ideas along these lines. Yes, I'm a rail geek. Sue me.)
No doubt cutting back on the Purple Line won't sit well with green-minded Evanstonians, who like transit in theory even if they don't use it in practice. But trains are only green if people ride them. If all they do is suck up resources, what's the point?
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