If diesel Caltrain were a car, it would be class as one of the heaviest polluters per passenger.

From Caltrain’s Great New Electric Trains Replace Heavy Polluters by Brad Templeton.

Promotional materials for the new trains tout that the switch will reduce greenhouse gas emissions by 250,000 metric tonnes per year, which is roughly the annual output of 55,000 cars, on average. The new electric trains will buy electricity only from zero-emission sources, according to Caltrain spokesperson Dan Lieberman. These numbers sound very positive, until you step back and consider their actual meaning, namely that the old diesel caltrain was using many times more fuel than its passengers would have burned if they each drove private SUVs, and that the train in general is hugely inefficient.

This is surprising, as the common public perception is that trains are more energy efficient than cars, and the initial instinct is to consider public transit as the greener choice. The math says otherwise, and in the case of Caltrain, it says it overwhelmingly. Nonetheless, this issue is not just one for this particular railroad, and applies to all systems, particularly in the U.S.

PROMOTED

The numbers mean Caltrain was burning about 25 million gallons of diesel annually. But today, Caltrain has around 590,000 boardings/year and an average of 24,600 on weekdays. That means 3.5 gallons of diesel per boarding, on average, which is equivalent to 4 gallons of gasoline. Each round trip thus burned the equivalent 8 gallons of gasoline per person. A 30 miles each way round trip in a car with the average load of 1.5 people, which is less that one gallon per person in a Prius, and 2 gallons per person in a large SUV. Even if each passenger were given a personal Hummer H2 to drive, they would only burn 4.6 gallons for that round trip. If diesel Caltrain were a car, it would be class as one of the heaviest polluters per passenger.

This happens because the trains don’t run full, and they run all day. Trains can, in theory, be very efficient, but only if they run full all the time. The most efficient trains in the U.S. are the commuter rail lines that run all the trains inbound in the morning, with all those trains staying at the station all day to take the commuters home in the evening. Those trains run fairly full and don’t run in the anti-commute direction or at off-peak times. Most passengers, though, want to know they can come and go when they wish and demand trains all day, which Caltrain offers. The theoretical efficiency of the train is good, but moving empty seats isn’t of value.

[snip]

Promotional materials for the new trains tout that the switch will reduce greenhouse gas emissions by 250,000 metric tonnes per year, which is roughly the annual output of 55,000 cars, on average. The new electric trains will buy electricity only from zero-emission sources, according to Caltrain spokesperson Dan Lieberman. These numbers sound very positive, until you step back and consider their actual meaning, namely that the old diesel caltrain was using many times more fuel than its passengers would have burned if they each drove private SUVs, and that the train in general is hugely inefficient.

This is surprising, as the common public perception is that trains are more energy efficient than cars, and the initial instinct is to consider public transit as the greener choice. The math says otherwise, and in the case of Caltrain, it says it overwhelmingly. Nonetheless, this issue is not just one for this particular railroad, and applies to all systems, particularly in the U.S.

PROMOTED

The numbers mean Caltrain was burning about 25 million gallons of diesel annually. But today, Caltrain has around 590,000 boardings/year and an average of 24,600 on weekdays. That means 3.5 gallons of diesel per boarding, on average, which is equivalent to 4 gallons of gasoline. Each round trip thus burned the equivalent 8 gallons of gasoline per person. A 30 miles each way round trip in a car with the average load of 1.5 people, which is less that one gallon per person in a Prius, and 2 gallons per person in a large SUV. Even if each passenger were given a personal Hummer H2 to drive, they would only burn 4.6 gallons for that round trip. If diesel Caltrain were a car, it would be class as one of the heaviest polluters per passenger.

This happens because the trains don’t run full, and they run all day. Trains can, in theory, be very efficient, but only if they run full all the time. The most efficient trains in the U.S. are the commuter rail lines that run all the trains inbound in the morning, with all those trains staying at the station all day to take the commuters home in the evening. Those trains run fairly full and don’t run in the anti-commute direction or at off-peak times. Most passengers, though, want to know they can come and go when they wish and demand trains all day, which Caltrain offers. The theoretical efficiency of the train is good, but moving empty seats isn’t of value.