People seem innately programmed to devote a fixed amount of metabolic energy–an average of 240 calories, or the energy in a hot dog–to traveling around each day, according to an analysis of the habits of thousands of people in England. That’s about a tenth of a person’s total daily energy outlay, the analysts say.
The finding may give transportation planners a new tool for predicting travel behavior, such as how much bike riding a person might do after his or her bus commute from work, says civil engineer Robert Kölbl of the University of Technology Vienna in Austria.