Personal Rapid Transit and Urban Development
The pattern of development and
redevelopment that may be induced by a particular form of
public transit is of prime importance to urban planners and
concerned citizens. The streetcar produced strip development
along its tracks. Since World War II, the automobile system
has taken over as the major factor in the growth pattern of
cities. The result has been what has become known as
"urban sprawl" and is considered by many to be
undesirable. Before examining the effect new transit systems
may have on urban development and redevelopment, it is
necessary to examine what it is that is undesirable about
urban sprawl and what if anything can be done about it. My
observations on this question come from discussions with
planners and geographers, from literature, and from several
decades of observation as an urban resident, which has
included many years of living in both high-rise apartment
buildings in the city and in the first-tier suburbs.
Urban sprawl in the United States has resulted from the
compounding of individual decisions as to where to live and
from the lack of enforceable land-use plans. The automobile
has been a prerequisite to urban sprawl but, by itself, could
not have produced it. In my experience, the fundamental
driving force has been simply the desire for privacy, fresh
air, closeness to nature, and a nice place for one's children
to run and play. In the early days of the auto, only the
wealthy could afford both a home in a nicely wooded area on
the outskirts of town and a car for transportation to the
office. The wealthy have influenced town politics and so were
able to get better and better roads to their isolated
communities. As these communities grew, they built schools
and of course they made certain that these schools were of
high quality.
Two more driving forces then came into play. First, the
desire of parents who could not quite afford it to take
advantage of the better education they felt their children
could get by attending suburban schools; and second, the fact
that taxes were lower outside the city limits. After World
War II, GI home loans with low down payments and low interest
and similar auto loans were the final factors needed for
development of a market for single-family suburban homes for
people of average income. Land developers were ready to
supply the market and, from the viewpoint of most of them,
profits would be maximized if every possible lot were
developed. Community objectives like parks and playgrounds
appear to not have been of prime concern to private
developers. Also, these facilities do not contribute directly
to the tax base. From the viewpoint of the individual family,
the move to the suburbs was a thrilling event. It would have
been difficult indeed to persuade people that there could
have been anything wrong with it.
Urban sprawl does, however, produce detrimental effects.
Some of them are the following:
1. The cost per dwelling of utilities is higher in the
lower-density suburban communities. When people first moved
to the suburbs the pattern was to have one's own cesspool and
well. Power lines were provided to meet the demand. As lots
filled up, cesspools became overloaded and wells
contaminated. Pressures built for sewers and water lines as
well as for better roads, schools and playgrounds thus
causing property taxes to go up, reflecting the real costs of
low-density living. As a minimum, it would seem desirable for
metropolitan authorities to fully inform families of the
obligations they will incur in moving to a new suburb. A
problem now is that the family is simply not aware of the
total financial burden it is assuming when making the down
payment. To so inform people would of course run counter to
past policies of encouraging maximum growth.
2. Low-density housing tends to isolate families and to
decrease the sense of community. In families that have been
able to afford only one car, the wife is much more isolated
than when she lived in town and could walk to many places of
interest. Margaret Mead has written and lectured in depth on
this topic. Quite evidently an important additional factor in
this isolation is the frequency with which Americans
move.
3. The cost per ride of providing public transit is
inversely proportional to population density. Thus, bus
systems that were economically viable in the inner city could
not survive in the suburbs. Lack of public transportation
increases the isolation of those with no access to an
automobile.
4. Conservationists have warned that too much valuable
farm land is going into housing and have calculated that if
this land continues to be gobbled up for a few more decades
at the present rate, the United States will have to worry
about an insufficient supply of good farm land. For example,
many formerly fertile agricultural valleys in California are
now smog-filled suburbs.
5. The lack of regional planning in the United States
has resulted in far too few good parks in the suburban areas.
As a counter example, in Minneapolis, foresighted community
leaders over eighty years ago caused the city to purchase
lands around a chain of lakes on the periphery of the city.
Many scoffed at such a ridiculous waste of public funds, but
these lands now form a chain of parks that are a prime asset
to the whole community. They not only have recreational
value, but have been an obvious factor in keeping many of the
more affluent within the inner city. The parks have been a
magnet to attract desired development. It is a real loss to
the whole metropolitan area that more recent community
leaders did not follow the example of there forefathers. As a
result, there are far too few parks in the suburban areas of
the Twin Cities. I have been persuaded that the current form
of urban development is detrimental and that policies should
be developed to shape growth in desirable ways. The basis for
these policies should be a very thorough quantitative
understanding of the underlying factors that have determined
current growth patterns, and that may determine growth
patterns in the decades ahead. It is important to appreciate
that for many reasons the future will not be a mere
extrapolation of the growth trends of the past. I am also
very aware of the quantitative arguments of people like Peter
Gordon and Harry W. Richardson in their online paper entitled
"Are Compact Cities a Desirable Planning
Goal?" [1].
People behave in their own best interest as they see
their interest, not as some planning group may see it. Some
of the policies I believed, at least when I first wrote this
report, should be developed (and in some areas are being
developed) are the following:
Identify and purchase appropriate lands for parks and
playgrounds.
Develop information for potential suburban homeowners in
order to inform them of the full potential cost of moving to
the suburbs.
Review and approve, by a central and democratically
elected authority, all requests to build roads, transit
lines, sewers, water lines, and power lines; and identify
areas in which such approval will not be granted.
Concentrate non-residential activities in well-located
major centers of predetermined maximum daytime population.
The maximum population of each should be determined from
consideration of the ability to supply all utilities
including transportation. These maxima should apply to the
downtown as well as to other major centers. The philosophy of
the greatest possible growth of any one center should be
abandoned as being socially undesirable to the community at
large.
Establish through research the desirable range of
population densities. We have pointed out difficulties with
too low a population density. Too high a population density
is also socially undesirable.
Create a transportation plan with sufficient capacity to
provide the needs of the above policies. Since the flow in
any transportation corridor is proportional to the average
trip length, a pricing system should be worked out to
discourage longer trips.
Within a framework of policies such as those suggested
above, it is meaningful to discuss the possible effect of a
particular mode of transportation on urban development. A
public transit system may have a significant influence on
urban development if it can attract a significant fraction of
the total number of trips within the urban area, not just to
the downtowns; and if it can help reverse the major driving
forces that cause people to want to move out.
In our auto-oriented cities, no conventional transit
system is able to fulfill these criteria in a significant
way. Bus lines can be changed too easily to influence
development decisions. Also, the service concept of
conventional bus lines fails to address the needs of people
and therefore fails to attract a significant fraction of the
trips. People are asked to bend their habits to meet the
needs of the system, i. e., waiting for vehicles, picking up
and letting off other people unconnected with one's own trip,
and transferring. New service concepts like door-to-door
subscription service or dial-a-ride may increase transit
ridership--a desirable goal--but they are too much like the
auto to produce changes in development patterns. Studies of
the influence on development of potential new
on-line-station, fixed-guideway transit, i. e., rapid rail or
so-called "light rail" transit, come to similar
conclusions because the cost per ride is too high in low and
medium density communities to build a sufficiently extensive
system. The cost per ride is too high both because of high
construction cost and because the service concept is too
inferior to the auto to attract many trips. These systems may
cause some concentrated development near downtown stations,
but will do practically nothing about urban sprawl.
Now consider
Personal Rapid Transit . If PRT does influence urban
development and redevelopment in significant ways it will
first have to be a very successful system in terms that will
be reflected in the cost per ride. For many reasons, we
believe the cost per ride will be close to if not below a
reasonable fare, particularly if the system is used for
movement of both people and goods. In the following
discussion, it is assumed that this is true and that properly
designed overhead guideways will be acceptable at least along
major arterial streets, freeways, and rail tracks; since only
then can PRT affect development decisions. Only by going to a
different level will it be possible the affect congestion. In
the downtowns, these guideways may be as close together as
two blocks, but in residential areas the lines more likely
would be placed along arterials one half to one mile apart. A
major point is that the location of the lines should be
determined in accordance with an overall development policy
and only with concurrence of the affected residents.
If PRT becomes accepted, there will be pressure to
extend the lines farther and farther into the suburbs. But,
if this is done according to a carefully developed plan, then
it need not produce the undesirable features of urban sprawl.
Because the system would be designed to be physically
attractive and quiet, residential communities could be
planned and built near the lines to minimize the walk to the
stations. The spaces farthest from the lines could be planned
as open spaces for a variety of purposes. Small electric cars
and bicycles could provide access for those too far from the
lines to walk. With a network of high-capacity PRT lines in
the inner city, the use of automobiles would reduce. This
would reduce the negative side effects of the auto, i. e.,
noise, air pollution, physical blight, accidents, excessive
land use, etc. Many parking lots could be restored to green
areas. Streets could be narrowed and partly converted into
linear parks thus further reducing auto traffic and
increasing the beauty of the city. The result would be a city
that would begin to attract and hold people rather than drive
them away.
Downtowns could restrict the use of automobiles without
causing economic stagnation because people would have a
viable alternative mode of travel, indeed an alternative far
more convenient as a means of access to downtown than exists
today. With easy access to the downtowns and other major
centers, people would go to them because of the attractions
they offer. It would thus seem that PRT would satisfy the
needs of downtown interests as well as the interests of the
community at large. Coupled with other policies, PRT appears
capable of producing significant positive influences on the
whole community.
I am reminded of a statement by Daniel H. Burnham in the
preface of a report of a comprehensive city plan developed
for Chicago in the early years of the 20th Century :
"Make no little plans; they have no magic to stir men's
blood and probably of themselves will not be realized. Make
big plans; aim high in hope and work, remembering that a
noble, logical diagram once recorded will never die, but long
after we are gone will be a living thing, asserting itself
with ever-growing insistence. Remember that our sons and
grandsons are going to do things that will stagger us. Let
your watchword be order and your beacon beauty."
This paper is based on the Appendix to a statement on
National Transportation Policy the author gave to the
Subcommittee on Department of Transportation and Related
Agencies Appropriations, U. S. House of Representatives,
March 6, 1974.
Citations:
[1]
www.smartgrowth.org/library/apa_pointcounterpoint/apa_sprawl.html
Last modified: October 17, 1998