Air, Rail or Bus?
Beth and I traveled to the graduation of a grandchild in Georgia. According to Mapquest, we could have driven the distance of 1,212 miles in 19.3 hours — a 39-hour round trip. We flew from Boston instead. To minimize driving and test our local transportation options, we drove to Brunswick and took the Concord bus to Logan Airport. We could have boarded the same bus near home in front of the Skidompha Library, but the only Maine Coast bus leaves Logan too early in the forenoon for us to take upon return. So, after a late afternoon arrival back to Logan, we took the “T” to North Station and the train back to Brunswick. It was a long, tiring, trip — but replete with lessons about the state of US transportation.
The flight to and from Atlanta took only 3 hours each way; however, with all the ground transportation and waiting in multiple airport queues, the trip stretched to 11 hours each way. Athens, our destination, is a major university town, yet it has no public transportation access. We had to fight Atlanta’s notorious I-85 traffic jams in both directions in a rented car. So, even though our jet’s ground speed exceeded 550 miles per hour, we traveled at an effective speed of only 110 mph.
Had we driven instead to Portland Jetport, we could have caught a flight from there. The nonstop flying time would have still been 3 hours each way, with ground travel and waiting times extending the trip to only 7.25 hours — boosting our effective travel speed to 167 mph. However a one-stop flight would have lengthened the trip to 12.2 hours, reducing the effective ground speed to 99 mph.
Both our flights were full. It took us over 10 minutes to disembark from our Airbus jet, giving me time to reflect on effective (i.e., real) travel speeds and the energy it takes to achieve them. If the engines of a 1 million pound airliner produce 200,000 lbs. of thrust to overcome the drag of the airplane—the wings do the lifting — my share of the thrust is 40 lbs. And my maximum effective speed of 167 mph is well below the speeds of high speed trains — Europe’s Thalys and TGV, Japan’s Shinkansen and China’s new high speed trains all travel at speeds between 200 and 300 mph. They also use a small fraction of the energy per passenger a jet airliner consumes.
It takes less energy to move mass by rail than in any other way — 8 pounds of force (1/248th of the whole weight) to move one ton of mass on a level railroad. That’s about 0.8 lbs. of force to move a person. To move the same ton of mass takes a 20 times greater force, 160 pounds (1/12th of the whole weight) on a level road — or 16 lbs. of force to move a person riding in a car or bus. This is because a steel wheel rolling on a steel rail is subject to 85-99% less rolling friction than a rubber tire rolling on an asphalt or concrete pavement.
So much for the physics of it. Other important factors, of course, include the distance traveled and the number of passengers on a given conveyance — subjects I will explore separately when also comparing costs.
What about comfort? There is no need to make your way to a distant airport to board a train or bus. You board and arrive in the city or town center. There are no security lines or extra charges for preferred seats or baggage. Getting on and off a train is fast, through multiple doorways. Everyone sits in comfortable, wide seats, with plenty of leg room. Passengers are free to move about the length of the train, enjoy a meal in the dining car, and so on.
Calculating my carbon footprint for our recent Georgia trip is somewhat tricky — driving, riding buses, trains and planes, all using different fuels at different efficiencies. But it is possible to convert all values to their gasoline gallon equivalents. We could then use 18.9 pounds of CO2 for each gallon of gasoline+10% ethanol consumed. More on this later.
After a pleasant walk to the station, imagine boarding a local train from Newcastle-Damariscotta to Portland, getting there in an hour, then speeding along to any major US city, doing 200 mph or more! Frankly, I’d gladly settle for 110 mph — the speed even some conventional European “fast” trains now routinely travel at — beating the one-stop air-travel time between Portland and Atlanta by 1 hour and 12 minutes.