The Evolution of Transport

to navigate. Our aim is to provide some fixed points derived from a technical analysis of transport systems that enables us to understand past travel and prepare for its future. Along the way, the lunacy of popular ideas such as car pooling, telecommuting, and the revival of traditional railroads will become clear. Instead, we will offer something far more beautiful: a transport system emitting zero pollutants and sparing the surface landscape, while people on average range hundreds of kilometers daily on a system of “green” mobility. In a spatially inhomogeneous system, living things are much favored by mobility. A couple of billion years ago bacteria were already equipped with rotating flagella, stirred by electric micromotors of the kind physicists call step motors, and even capable of traveling in reverse. When a sufficient level of oxygen permitted multicellular architecture, mobility was assured with specialized structures, the muscles. Coordination of the distant muscles of an animal requires a central processing unit and fast wires to carry sensory inputs as well as operational orders. Predators develop in every ecosystem, including that of the monocellular organisms. The evolution of the nervous system, thus, responds to the need for management at a distance. The gazelle must be faster than the lion and have the chance to run. Human primacy in the biosphere is tied to the nervous system, and our development shows how much we owe to the necessity of mobility. Human mobility stems from four basic instincts. These instincts permit analysts to create a simple model for the complex use that humans make of transport. The first travel instinct is to stick to the budget of time dedicated to mobility (Figure 1). Humans reside in a protected base, be it a cave, a castle, or a high-rise apartment. Like all animals who have a protected base, we carefully measure the time in which we expose ourselves to the dangers of the external world, be they bears or d r u n ken drivers. The late Yacov Zahavi measured travel time in the 1970s. The results were invariant, about one hour per d a y, measured over the year and the entire adult population. Recent measures give the same result from Au s t r a l i a to Zambia. California is higher than the U.S. average because Californians spend more time doing other things in their cars, including eating. Interestingly, the traveltime budget was also about one hour 5,000 years ago. Telecommuting fails to save energy or reduce traffic because when we travel fewer minutes to work, we travel equally more minutes to shop or pursue leisure activities. The second instinct is to return to the lair in the evening. When people depart from the home, the center of the human world, they use the best means of transport. The homing instinct lies at the core of the success of airlines. Airbus Industries found that about 60% of air passengers in Europe do their business and return on the same day, notwithstanding the higher fare. Shuttles operating from New York and Los Angeles carry a similar proportion of day-trippers. Revived and sustained at great cost, the trains between Boston, New York, and The Evolution of Transport