Sure, studying transportation is important if you need to find the best route to the hardware store. But you might be surprised to know that transportation study might have other uses, like enlightening you about the most profound philosophical mysteries of the universe. For example, transportation might just tell us some surprising things about the degree to which we truly have free will.
We think we decide when, where, and how we journey, but despite our illusion of control it?s quite possible that we are in the grip of mysterious forces that dictate our travel patterns. Are we marionettes with travel pulling the strings?
A. Schafer and D.G. Victor published a paper in which they examined dozens of studies on how much time people spend traveling. The settings for these studies were quite different?including African villages and cities in communist Eastern Europe, as well as modern Latin American, Asian, Western European and American locales?but overall, travel times were surprisingly similar.
Virtually every study found that its region?s residents travel, on average, between about 45 minutes and 1.5 hours per day. The average for all regions was about 1.1 hours. Given that the technological endowments, political systems, cultures, religions, incomes, transportation systems and land use patterns of these places are quite different, the regularity in daily travel times might be viewed as pretty noteworthy.
Based on this it is tempting to speculate that there is some sort of innate Travel Time Budget (TTB) built into human beings. The TTB theory holds that the time we spend traveling is relatively fixed, leaving us with strikingly little ultimate control, appearances to the contrary.
Going even further, Yacov Zahavi (a pioneer of the TTB theory) and like-minded scholars maintain that people across times and cultures tend to spend a constant fraction of their money, as well as their time, on transportation. Schafer and Victor assembled data on the percentage of their expenditures that people from a range of rich-world societies devote to travel. Excluding the odd case of Japan (which featured an atypical amount of high-speed public transport, plus high price levels for other goods), the data points cluster pretty tightly in the range of 8 to 15 percent, again despite very different national situations. Score another point for determinism over free will.
Proponents of the TTB theory admit some factors do cause travel time and money budgets to vary. For example, residents of big cities spend more time traveling than others, and those with cars devote a larger share of their incomes to travel than those without them (hence the low expenditure rates for the developing countries). Still, though, proponents of TTB maintain that regularities in expenditures of both travel time and money outweigh the differences.
As when Einstein determined that the speed of light is fixed, which leads to the rest of nature having to resort to some bizarre tricks, fixing total travel time leads to odd fluctuations in other aspects of the transportation equation.
For example, what happens when those African villagers eventually buy cars and can make a journey to the market in only minutes when it used to take hours? According to TTB proponents, they do not apply the time savings to other activities, but instead devote them to other types of travel. More mobility leads to more frequent trips, and, especially, to trips that are longer in physical distance. Thus, those who acquire an auto may make a grocery shopping trip to a distant supermarket or warehouse club instead of to the neighborhood market on the corner.
What might account for stable transportation budgets? Well, for one, until we start colonizing other planets there are only 24 hours in the day. Take out time for all of the essential activities like sleeping, eating, working, grooming, child rearing, shopping for essentials, etc., and the residual which one can devote to travel obviously has an upper bound. Still, this does not explain the hypothesized lower bound, which is considerably more mysterious.
Cesare Marchetti has theorized that the travel time budget is the product of evolutionary pressures stretching far back into our pre-agriculture past. He sees the desire to travel as part and parcel of an instinct to expand our territory, with all of the tasty roots, berries and wooly mammoths that were the lives? ambitions of our distant ancestors.
However, territorial expansion was not without its costs; travel involved danger from god knows what crazy predators might be stalking out there, plus those pesky headhunters on the other side of the river. Also, travel is simply hard work. In addition, Marchetti maintains that man balanced wanderlust with a cave instinct; the urge to turn into a couch potato apparently far predated the invention of the couch or the discovery of the potato.
So Mother Nature is held to have settled on a rough balance between home and away, and to have programmed us with a primal travel urge to maximize our survival and the survival of those who are in one way or another responsible for the propagation of our genes.
Why is TTB important? In addition to its sheer freakworthiness, it might have considerable practical import. Schafer and Victor believe future travel patterns can be extrapolated using the TTB law.
So in all this is a great theory, which has but a single minor drawback: it might not be true. A favorite scholar of mine, Patricia L. Mokhtarian, and her colleague Cynthia Chen have carefully reviewed the evidence on the TTB. Their findings soon.