Edit: I am not advocating people stop exercising or drive everywhere, this was just a simple stat limited to the scope mentioned below. There are of course health benefits to walking and environmental trade offs associated with driving.
Inspired by a Wikipedia article I came across on energy efficiency in transportation, I decided to compare the cost of the various transportation methods. In order to do this, I split the cost calculations into the following two groups:
- Self-powered transportation (walking, running, and biking): I calculated the average calories burned per mile from the mentioned self-powered transit modes, along with the associated cost per calorie. Using this information, I could then determine how much it would cost per mile to “fuel” this transportation.
- Fuel cost per mile = calories burned per mile/cost per calorie
- Motor transportation (cars, trains, etc): First, I pulled the energy (in kWh) required to travel 1 mile for each mode from above Wikipedia article, along with the gasoline equivalent of said energy consumption. Next, I paired this with average gas costs to determine the energy cost per mile.
- Fuel cost per mile = gasoline required per mile/cost of gasoline
note: there is also some basal metabolic rate each of us has that will burn calories during non-active motor transport, but the assumption here is that the caloric burn through walking, biking, and running are additive to this base rate, meaning it’s ‘extra’ fuel required
Fueling walking costs 3 times more than fueling your car:
Surprisingly, from a pure energy perspective (using the methodology mentioned above), biking, walking, and running are the three most expensive types of transportation listed:
Now, the above chart uses the average American daily food expense of $7.00, paired with an average caloric intake of 2500 calories per day, for a $0.0028/calorie cost. Some of you may look at this $7.00 per day and say, “I can do better than that”; to this I say, how about a McDonald’s-only “complete/nutritious” diet running you $4.40 per day or $0.00176 per calorie (a ~37% reduction from the American mean).
Sadly, biking, walking, and running still check in as the most expensive forms of transportation to fuel.
Even on a McDonald’s only diet it’s more expensive to fuel walking compared to driving:
I know, I know, McDonald’s isn’t that cheap. We can do better. How about only eating (drinking) pure vegetable oil (aka pure fat) to fuel these activities? A gallon of vegetable oil will run you $5.76 and provide 30,720 calories, for a cost per calorie of $0.000194 (a 93% reduction in food expenses from the American average, and an 89% reduction from our McDonald’s scenario).
A vegetable oil only diet will make biking, walking, and running cheaper to fuel than driving:
Considering total cost of car ownership in calculations:
The above scenarios were simply comparing fuel costs between the transportation types, but there are, of course, a number of additional costs tacked on to owning a car. Using AAA’s average cost per mile of ownership of $0.34, and pairing it with our already-calculated fuel cost we arrive at a $0.40 per mile total car transportation cost.
Plugging in the total cost to own for the car, and comparing with biking, walking, and running, we can see it’s anywhere from 33-400% more expensive to drive, depending on activity type.