Paved Area Tabulations
For land area consumed by roads in the United States
GIVEN:
Road length.1
Roads were broken up into the following categories: interstates, other
freeways and expressways, other principal arterials, major and minor collectors,
and local roads, for both rural and urban areas in the United States.
(Given in miles.)
Average number of lanes and
lane width by road type. 2
Because of varying nomenclature between the two reports for rural road
systems, measurements for the United States Federal Highway Administration’s
“other principal arterial ”designation were taken as an average
of the estimates for“other highway and principal arterial.”
(Width given in feet.)
Shoulder and divider width.
3 Shoulders and dividers
were only assumed to take up significant land area in rural areas. (Given
in feet.)
Private paved road factor.
4 This
coefficient was used to account for paved roads that were privately owned
and thus not taken into consideration in federal estimates of road length.
ASSUMED:
Right-of-way width.5
The United States Federal Highway Administration Real Estate Office provided
rough estimates of the width of tracts purchased for roads. These ranged
from 50 feet wide for smaller roads in rural areas, to a minimum of 500
to 600 feet wide for many interstates. Because the right-of-way would
only take up significant areas of potential farmland in rural areas, this
measurement was only applied to rural road width, starting from a conservative
50 ft. width for local roads, and increasing at increments of 50 feet
with each respective increase in road size.
CALCULATED (For each
type of road):
Actual road width = (Average # of lanes)
x (Average lane width)
Total effective road width = (Actual
road width) + (Shoulders & dividers) + (Right-of-way)
Area Consumed By Road = (Total effective
road width) x (Private road factor) x (Road length)
For total land area consumed by the car in the United States
GIVEN:
Size of vehicle fleet.6
Includes cars plus commercial vehicles.
Area of parking space.7
Each parking space is assumed to take up 30 square meters.
ASSUMED:
Number of parking spaces per vehicle.
It was assumed that for every car in the United States, there must be
at least 3 off-road parking spaces. These spaces include room to park
in places of residence, workplaces, schools, shopping centers, and hospitals.
This estimate does not account for spaces in multi-level or underground
parking areas as it concerns the strict area of land that is lost to the
car.
CALCULATED:
Area Consumed By Parking = (Size of vehicle
fleet) x (Number of parking spaces per vehicle) x (Area of parking space)
TOTAL AREA DEVOTED TO VEHICLES
= (Area Consumed by Road) + (Area Consumed by Parking)
For land area consumed by road in other selected countries
The relationship between the total road length and the
area consumed by cars (including parking) in the United States was used
to calculate a conversion factor of number of hectares of land consumed
for every kilometer of road. The area consumed by road in Canada and Mexico
was tabulated by multiplying the total road length in each country by
the conversion factor. The same conversion factor was used for these North
American countries under the assumption that they had followed a similar
sort of transportation infrastructure development because of their relatively
low population densities.
Because populations in the European Union and Japan
are relatively more densely concentrated than in the United States, the
conversion from length of road to paved area was discounted for these
countries. The average road distance per vehicle for Japan, France, Germany,
and the United Kingdom was calculated and then divided by the road distance
needed for each vehicle in the United States (30 meters per vehicle).
It was assumed that the older roads in these countries of higher population
density would be about 80 percent as wide as those in the United States.
Multiplying the fraction of road distance per vehicle of the EU and Japan
over the United States by 80 percent, a discount rate by which to convert
the land area devoted to the car in the selected countries was determined
to be approximately 45 percent.
SCENARIOS:
For potential land area consumed by road in India and China
Vehicle ownership level is defined as the number of
vehicles per thousand people in a given country. The vehicle ownership
level of industrialized countries is at least 500, or one car for every
2 people. This industrial vehicle ownership level was used along with
the current vehicle fleet size in India and China to calculate the necessary
fleet size increase if India and China were to reach industrialized automobile
ownership levels.
Because the populations of India and China are relatively
concentrated, it was assumed that each automobile would consume an area
of land similar to that of France, Germany, and the United Kingdom, which
is 0.02 hectares of land for each automobile. This factor was used along
with the road length of the 2 countries to calculate the total "paved"
area needed to accommodate the potential automobile fleet size increase.
GIVEN:
Current vehicle fleet size.8
Includes cars plus commercial vehicles.
Total road length 9 Note
that the portion of unpaved roads in India and China is higher than in
the previously analyzed industrialized countries, but the effective "paved"
area is calculated in the same manner. This is because the effective land
area lost for a road is roughly the same, regardless of the manner of
construction.
ASSUMED:
Industrialized vehicle ownership level (IVOH).
This is assumed to be at least 500 vehicles for every 1,000 people.
CALCULATED:
Vehicle fleet size at industrialized vehicle
ownership level (IVOH)= (Current fleet size) x (IVOH)/(current
vehicle ownership level)
Total potential “paved”area
with fleet increase = (Vehicle fleet size at IVOH) x (0.02 hectares/vehicle)
FOOTNOTES
1. United States Department of Transportation,
Federal Highway Administration (US FHWA), Highway
Statistics 1999 (Washington, DC: 2001).
2. Mark Delucchi, “Motor Vehicle Infrastructure and Services Provided
by the Public Sector,” Annualized Social Cost of Motor-Vehicle Use
in the U.S., Vol. 7, Institute of Transportation Studies, 1998, cited
in Todd Litman, Transportation Land Valuation
(Victoria, British Columbia: Victoria Transport Policy Institute, November
2000), p. 4.
3. Ibid.
4. Mark Delucchi, op. cit. note 2.
5. David Walterscheid, US Federal Highway Administration Real Estate Office,
personal conversation, February 2001
6. Ward’s World Motor Vehicle Data 2000.
7. Dr. Jeffrey Kenworthy, Associate Professor in Sustainable Settlements,
Institute for Sustainability and Technology Policy, Murdoch University,
Australia.
8. Ward’s World
Motor Vehicle Data 2000.
9. United States Central Intelligence Agency (CIA), The
World Factbook 2000 (Washington, DC: 2000).
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Other data: World Automobile
Production and Fleet, 1950–2000
Contact: Janet Larsen, jlarsen(at)earth-policy.org
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