On the road again: how tax policy drives transportation choice

Virginia Tax Review, Wntr, 2005 by Roberta F. Mann

B. Land Use and Development

The automobile made low density, residential-use-only suburbs possible. (25) In the early twentieth century, the architect Frank Lloyd Wright popularized the ideal of the single family home on a green suburban lot. (26) Pro-suburban government policies in housing, transportation, and education facilitated this consumer preference. (27) Recent development has focused outside the central city, in suburbs and exurbs. (28) As low density development increases, transportation options decrease, until the only practical option for most Americans is the private motor vehicle. (29) In 2002, U.S. workers made 77% of trips to work by driving alone. (30) Of the total trips to work, 10% carpooled, 5% took public transit, 2.5% walked, 3.5% worked at home, and the remainder found other ways to work such as bicycle or motorcycle. (31)

Urban planning, encouraged by government subsidies, focuses more on what the automobile needs rather than what the community needs. (32) The automobile needs roads, parking, and fuel. People need access to work, shops, and recreation. As will be illustrated, when the automobile's needs are put first, human needs suffer.

1. Road Building

Conventional wisdom says the solution for congestion is more and bigger roads. (33) However, road building is a supply-side strategy that doesn't work. (34) Anthony Downs used the term "triple convergence" to explain why building capacity doesn't reduce congestion. (35) Triple convergence refers to the three types of behavior that occur in response to roadway improvements--spatial, time, and modal convergence. (36) Spatial convergence means that drivers that took alternative routes will flock to the improved road. (37) Time convergence means drivers who had responded to congestion by leaving earlier or later will revert back to peak travel times. (38) Modal convergence means that commuters who had taken public transit switch to driving, as increased road capacity temporarily affords a faster trip. (39)

Urban congestion unquestionably has gotten worse. In seventy-five urban areas studied by the Texas Transportation Institute, 46.9 million additional miles of person travel were added in 2001. (40) Commuters spent an average of twenty-six hours in traffic jams in 2001, up from seven hours in 1982. (41) In 2001, congestion cost $69.5 billion, attributable to 3.5 billion hours of delay and 5.7 billion gallons of fuel wasted. (42) Congestion delays cost an average of $523 per person in 2001. (43) The wasted fuel would fill 114 supertankers. (44) In very large urban areas, delays grew 300% from 1982 to 2001. (45) For medium sized urban areas, delays grew even more, an increase of 650% from 1992 to 2001. (46)

Sprawl and population growth combined with low-density housing patterns leading to automobile dependence are the primary causes of traffic congestion. (47) Population growth, contrary to popular belief, is the smallest part of the picture. Since 1982, the population in the metropolitan areas studied by the Texas Transportation Institute increased by 22%, miles of highway increased by 33%, and the average traffic delay increased by 235%. (48) Population growth accounted for only 13% of the increase in driving, while sprawl accounted for 69% of the increase. (49) "Development patterns that require an automobile trip for every errand force us to drive more every year to accomplish the same things." (50) Moreover, road capacity has more than kept pace with population growth, without corresponding benefits in reducing congestion. The theory of triple convergence seems to be accurate--spending money on more road capacity does not seem to lessen congestion. In fact, one study found the more an area spent on road construction, the more congestion it experienced. (51)