Environmental Engineering Reference
In-Depth Information
U.S. rate. According to environmental leader Lester R.
Brown, China would need slightly more oil each year
than the world now produces and would have to pave
an area equal to half of the land it now uses to produce
food.
7-7 TRANSPORTATION AND URBAN
DEVELOPMENT
Land Availability, Transportation Systems,
and Urban Development
Land availability determines whether a city must
grow vertically or spread out horizontally and
whether it relies mostly on mass transportation or
the automobile.
If a city cannot spread outward, it must grow verti-
cally—upward and downward (below ground)—so
that it occupies a small land area with a high popula-
tion density. Most people living in
compact cities
like
Hong Kong and Tokyo walk, ride bicycles, or use
energy-efficient mass transit.
A combination of cheap gasoline, plentiful land,
and a network of highways produce
dispersed cities.
These are found in countries such the United States,
Canada, and Australia, where ample land often is
available for outward expansion. Sprawling cities de-
pend on the automobile for most travel, which has a
number of undesirable effects (Figure 7-17). Neverthe-
less, motor vehicles are increasing in both compact
and dispersed cities.
Advantages and Disadvantages
of Motor Vehicles
Motor vehicles provide personal benefits and help
fuel economies, but they also kill many people,
pollute the air, promote urban sprawl, and lead to
time- and gas-wasting traffic jams.
On a personal level, motor vehicles provide mobility
and offer a convenient and comfortable way to get
from one place to another. They also are symbols of
power, sex, social status, and success for many people.
For some, they provide temporary escape from an in-
creasingly hectic world.
From an economic standpoint, much of the
world's economy is built on producing motor vehicles
and supplying roads, services, and repairs for them. In
the United States, for example, $1 of every $4 spent
and one of every six nonagricultural jobs is connected
to the automobile.
Despite their important benefits, motor vehicles
have many harmful effects on people and the en-
vironment. They have killed almost 18 million people
since 1885, when Karl Benz built the first automo-
bile. Throughout the world, they kill approximately
1.2 million people each year—an average of 3,300
deaths
Case Study: Motor Vehicles
in the United States
Passenger vehicles account for almost all urban
transportation in the United States. Each year
Americans drive as far as everyone else in the world
combined.
America showcases the advantages and disadvantages
of living in a society dominated by motor vehicles.
With 4.6% of the world's people, the United States has
almost one-third of the world's motor vehicles, with
one-third of them being gas guzzling sport utility ve-
hicles (SUVs), pickup trucks, and vans.
Mostly because of urban sprawl and convenience,
passenger vehicles are used for 98% of all urban trans-
portation and 91% of travel to work in the United
States. About 75% of Americans drive to work alone,
5% commute to work on public transit, and 0.5% bicy-
cle to work. Each year Americans drive about the same
distance driven by all other drivers in the world and in
the process use about 43% of the world's gasoline!
According to the American Public Transit System, if
Americans increased their use of mass transit from the
current rate of 5% to 10%, it would reduce U.S. depen-
dence on oil by 40%.
Many governments in rapidly industrializing
countries such as China want to develop an automo-
bile-centered transportation system like that in the
United States. Suppose China succeeds in having one
or two cars in every garage and consumes oil at the
per
day—and
injure
another
15
million
people.
In the United States, motor vehicle accidents kill
more than 43,000 people per year and injure another
5 million, at least 300,000 of them severely.
Car ac-
cidents have killed more Americans than all wars in the
country's history.
Motor vehicles are the world's largest source of air
pollutants, which cause 30,000-60,000 premature
deaths per year in the United States, according to the
Environmental Protection Agency. They are also the
fastest-growing source of climate-changing carbon
dioxide emissions—now producing almost one-fourth
of them.
Motor vehicles have helped create urban sprawl.
At least a third of urban land worldwide and half in
the United States is devoted to roads, parking lots,
gasoline stations, and other automobile-related uses.
This fact prompted urban expert Lewis Mumford to
suggest that the U.S. national flower should be the
concrete cloverleaf.
Another problem is congestion. If current trends
continue, U.S. motorists will spend an average of two
years of their lives in traffic jams. Building more roads
may not be the answer. Many analysts agree with
