Blog 1
WANTS AND NEEDS
John Rowat, Environment Officer

Every time I travel to North America, I end up thinking about the sustainability of cities, and urban sprawl. Urban sprawl is the rapid expansion of the geographic extent of cities that have low-density residential housing, accompanied by single-use zoning and heavy reliance on the private automobile for transportation. North Americans do not have a monopoly on urban sprawl, but they have more of it than anyone else.

Visitors to Europe from North America often remark on the charm of old-world cities like Vienna. While not diminishing the importance of imperial ambition, siege fortifications, or Hippodamus of Miletus (5th century BCE architect and urban planner), much of the appeal and livability of old-world cities has simply to do with their scale. The scale of cities, ancient and modern, can be explained by Marchetti’s Constant.

Marchetti’s Constant is the duration of the daily commute we’re prepared to live with, an hour in transit every day. A half an hour either way is about as long as we’re prepared to travel to and from our place of work. It should be understood that Marchetti’s constant represents an average. Variation amongst individuals means that some are willing to travel longer whilst some prefer shorter trips.

Cesare Marchetti (1927-2023) concluded that this time scale is “hard-wired” into each of us. He came up with all of this while he was a researcher at the International Institute for Applied Systems Analysis in Laxenburg, just south of Vienna. His analysis is published in a 1995 paper titled “Anthropological Invariants in Travel Behaviours”. The paper is easily sourced online.

Marchetti studied things like modern Greek villages, ancient Rome, transportation modalities, and how cities like Berlin evolved over two centuries. A couple of the more interesting observations in his paper are: “The accent can be set, then, on transportation as the unifying principle of the world, and not on communication as the current wisdom indicates”. “Personal travel appears to be much more under the control of basic instincts than of economic drives.” One author summarized Marchetti’s research as… “the bedrock of civilization is not what we talk about but how we get to the meeting.”

Rome of 275 AD and Paris of 1383 were walking cities. London of 1870 was one of the first cities to transcend the ancient limits of urban development. The “Tube” made London a rail city. Chicago in 1915 was a city whose geographic extent was made possible by the tram. The geographic extent of Atlanta in 2010 reflects how the automobile has changed our living arrangements. The geographic extent of each of these cities conforms to Marchetti’s Constant. You could also add the Shinkansen train in Japan to the list of transportation modalities. The image below illustrates the scale of transformation created by the various modes of transportation.

Map

The geographic extent of Rome (275 AD), Paris (1383), London (1870), Chicago (1915) and Atlanta (2010). [Image taken from Marchetti’s Constant: The curious principle that shapes our cities, Frank Jacobs, bigthink.com, 8 Sept 2019.]

Recently we spent a few days with a teacher friend from Canada. She told us just how difficult and disruptive the COVID period was for students and teachers alike, something I had not appreciated fully. Teaching delivered by Zoom was no substitute for face-to-face learning. Of course, the same consideration applied to church services, workplaces, the performing arts, etc. In all of these situations, there was abundant want and need for face-to-face contact, and we had the means to make the half-hour journeys, however, prevention of the spread of infection prohibited us from doing so.

The COVID period was in many ways a prelude for the challenge ahead of us in respect of care and wise use of creation. Stewardship of creation will require us to adopt more sustainable living arrangements and require that we bring global warming under control.

xFor more than 10,000 years, Cesare Marchetti’s constant has held sway over where we place our homes, how we get to and from work, and how we build communities. For all but the last 100 years or so, all of those hour-long daily commutes have been done on foot. Going forward, we will need to reconcile behaviour reflected by Marchetti’s Constant – behaviour hard-wired into each of us – with imperatives for stewardship of creation. The teachings of Christ seem to be very well suited for this challenge.