Comparing gasoline's kilocalories to the range consumed in exercise, we find that a bicyclist could easily achieve the equivalent of one thousand miles per gallon, even at a relatively brisk pace.
So there it is - 1,000 miles per gallon. That is pretty darn efficient. The nice thing is that most of us, with our super sized meal portions, already consume enough energy to transport us to our daily destinations. So you really don't have to plan on upping your grocery budget. Our grocery budget panned out quite nicely for the month of January according to our month end financials (not yet audited).
Even when the Prius evolves into a fully electric plug-in green machine, weaned from the petroleum teat, driving it will still be inordinately consumptive of energy and tremendously inefficient compared to riding a bicycle. Conversely, the bicycle-and rider amplifies the human engine's power with levers and gears and wheels, while adding very little extra weight. Human legs that pack only a tiny fraction of the Prius's punch still have more than enough to move the bicycle-and-rider at speed.
He goes on to write that biking is four times as efficient as walking. I don't know if he is taking hills and wind into consideration on that one. I can actually visualize an efficiency gauge on our handlebars (like the gauge in a hybrid) plummeting as we are riding into that north wind.
Nothing--not commuter rail, biofuel buses, Prii, or pedestrians--can approach the efficiency of the bicycle. Bicycling stands completely above other transportation modes in that regard.
So next time you see that goofy little smart car, just remember that the smug little driver is not as smart as he or she might think. There is a smug little cyclist out there somewhere who is way smarter in the end.