I recently had to spend a couple of weekends in a city about 200 miles a way. Two of us traveled there by car; I figure per passenger $20 for gas and $17 for
fixed and maintenance costs (not including depreciation and other "soft" costs). So $37. And
five hours since we timed it to hit rush hours for three cities and a large military base.
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Coming back, I took Amtrack for $46, 3.5 hours, on time beginning and end. Walked the 3.5 miles home in 75 minutes (mostly uphill with short stops along the way for a pizza by the slice joint and later for a milkshake at Dick's, thereby removing any health advantage I might have gained by walking).
Returning the next weekend, jogging (I thought I was late) to the 3.5 miles to the BOLT bus stop, with just a $26 fare, and a 3 hour travel time (though a 30 minute late start), and notably less comfortable than the train.
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Next time? Driving a car that gets 40 mpg hiway instead of 20 would bring the car cost to $27, comparable to the bus. But when including environmental factors, Amtrak wins. The
respective CO2 emissions (in kg per mile) for gas-driven car, bus, and rail are 0.44, 0.3, and 0.16. Hybrids or all-electrics could change this but probably not by a factor of 3.