Commuting
Driving Works
Robert Bruegmann 07.29.08, 6:00 PM ET

Recently, there has been a rush by pundits, particularly those who live at the center of large, older cities, to claim that rising gasoline prices will lead inexorably to fundamental shifts in the way Americans live and work. They confidently predict a long-term decline in automobile use, a rise in mass transit ridership, a widespread move of families from the suburban periphery back to the central city and the demise of the McMansion and the SUV.

These predictions are based more on wishful thinking than on good evidence. They are, first of all, suspiciously similar to those made during the oil crisis of the 1970s. Like those of the 1970s, they are based on the notion that low-density suburbs, single-family houses and private automobiles necessarily consume significantly more energy than higher-density urban areas, apartments and public transportation.

This notion is based on an entire set of assumptions that is dubious at best. The first is that we will continue to use carbon fuels for most of our energy needs. This is unlikely. And even if we continue to use gasoline for most transportation needs, the assumption that public transportation will save a lot of energy is unfounded.

Public transportation, which in the U.S. is overwhelmingly via bus, does not use significantly less fuel per passenger mile traveled than private automobiles, because buses get such low gas mileage and carry so few people. This is particularly true once all of the bus runs, including the nearly empty runs outside peak travel times, are counted in. So even with 1.25 people per car, the average car today uses no more energy per passenger mile traveled than the average bus.

The idea that large numbers of families will move from the suburban periphery to the urban center to be closer to their jobs and avoid traffic is also problematic. The pundits tend to think that the rise in traffic in our urban areas has been caused by longer and longer commutes. In fact, the commute between home and work accounts for a surprisingly small percentage of all trips, less than 20%, and that number is falling. So merely moving closer to work would help only if it involved moving closer to everything else that a family does during a typical day.

In fact, the idea that moving people from the suburbs to the city will reduce traffic is probably wrong to start with. The major reason for the growth in traffic in U.S. cities has been that, as Americans have become affluent, more of them have been able to switch from public transportation to faster and more comfortable private transportation. And since the 1960s they have done so without any commensurate increase in the capacity of our roadway system.

For this reason, traffic is typically worst not in our most sprawling metropolises, places like Kansas City, Mo., but in places like Los Angeles, which (perhaps surprisingly) is the nation's densest urbanized area. Because of the vast growth in population and density in the L.A. region but no comparable growth in the freeway network since the 1960s, it has one of the smallest provisions of freeway lane miles per capita of any urban area in the country.

If there were any large-scale move of citizens from the edge to city centers, the rising densities would almost certainly further exacerbate travel problems, because, outside of central New York and Chicago, the percentage of people using mass transit is extremely small. The vast majority of residents would continue to drive automobiles, further choking already congested roads.

Even more basic is the proposition that moving back toward the center would decrease the length of commutes. This flies in the face of evidence that jobs have been moving outwards in urban regions for decades. Today no more than about 20% of the jobs in America's largest urban regions are located within three miles of the city center, and the growth in jobs in the suburbs has vastly outpaced that in the central city.

So much for short-term prospects. What of the future? As everyone's expectations of mobility have risen over the last decades, there has been an ever greater desire to find the most efficient way of getting directly from any given Place X to Place Y. This has given the automobile a tremendous edge over mass transit. With the rapid rise in congestion in many urban areas, the advantages of the automobile have declined slightly, but it is more likely than ever that in the future most people will use some combination of private or rental automobile, taxi or small on-demand vehicle than they will start using those old-fashioned, big-box transit modes, the bus or the train.

Traditional transit use may well increase a little in the short run, as it did in the 1970s, but in the long run it is very unlikely to offer most Americans an effective way to get to most of the places they need to go. Mass transit currently accounts for no more than about 5% of total trips in America's urban areas. To scale this up even to 25% would require a staggering capital expenditure and a remaking of urban patterns that would almost certainly be unacceptable to most Americans.

Yes, the current rise in fuel costs may well bring major changes to American urban development patterns and commuting patterns, but these price increases will hit city and suburb alike. The world is almost certainly on the verge of enormous technological change in energy generation and transportation. It is likely that this will, indeed, fundamentally reshape the way we live, but what these changes will be is hard to say. What is not likely is that this reshaping will look anything like the simpleminded predictions of the prophets heralding the death of the SUV.

Robert Bruegmann, a historian of architecture, landscape and the built environment, is a professor of art history, architecture and urban planning at the University of Illinois at Chicago. His most recent book, Sprawl: A Compact History, was published by the University of Chicago Press in 2005.