Megalopolis - Urban Environment
Throughout Megalopolis, the urban forms and urban functions provide the most significant regional unity to the territory. Tall buildings, busy streets, crowded housing, and industrial plants accompany an array of cultural opportunities - theaters, symphony orchestras, art museums, and large libraries. Also apparent is deterioration - dilapidated structures, traffic congestion, and air pollution. All of these and more are present in the metropolitan areas of Megalopolis.
These characteristics are also found in most large cities around the world. What distinguishes Megalopolis is that the urban characteristics in this region have spread so far from their core cities that the urban regions began to merge with one another in a process of metropolitan coalescence. Megalopolis became in this way a kind of gigantic laboratory in which intensively urban patterns and peculiarly urban problems could be observed developing at a very large scale.
Population densities in Megalopolis are high, averaging about 305 persons per square kilometer in 1987. Of course, some peripheral counties have populations that are only 10 to 20 percent of the region's overall average density. Settlement density increases as a city is approached, until very high densities are reached near the city core. In New York City, for example, 1987 densities exceeded an average of 226 persons per square hectare, which amounts to more than 22,660 persons per square kilometer.
What other features of city organization are associated with this density pattern? Modern cities result basically from the locational consequences of economic activities. When someone decides to move or to relocate a business into a city, the economic advantages of such a choice fundamentally dominate the decision. So pervasive are these advantages that large numbers of people live close to one another, often closer than they would prefer, and tolerate many negative consequences to participate in the benefits of city organization.
An increasing number of urbanites, however, minimized some disadvantages of city living by moving their residences to suburban locations. Others moved even farther, into a zone referred to as exurbia. From small towns, areas of converted vacation homes, and rural estates, exurban commuters travel to distant workplaces. But this spread of population has not eliminated the disadvantages of clustering, only shifted the population facing them. It has also spread the workplaces for those living in the region; a smaller proportion of a sprawling metropolitan population than previously still finds it necessary to enter the central city for work.
A key component of the urban landscape is interaction. In general, the cost of moving something is directly proportional to the distance it must be moved. Activities therefore cluster in cities so that movement costs are minimized. The importance of the ability to move from one place to another in urban regions is evident from the high proportion of urban land devoted to facilitating interaction. The lines of interaction for human movement are visible in streets, subways, bridges, tunnels, sidewalks, and parking lots. In older cities such as those in Megalopolis, the downtowns were laid out when travel was by foot and horse-drawn carriage; therefore, these cities have only about 35 percent of their total central areas devoted to landscape features that support human interaction. In newer cities, developed largely after the rise of the automobile, the proportion is much higher.
Other forms of interaction may be equally important but less visible. The easy movement of information and ideas is supported in cities by the intensively developed telephone, telegraph, teletype, and other communications systems. Ninety years ago, the central business districts of all large cities were crowded with spiderweb networks of telephone lines, testifying to the intensity of communication demands; today, telephone lines are wound into cables and placed underground.
Perhaps the prime motivation for interaction is the geographic separation of supply and demand. Economically, if an item or service is needed at a location that cannot meet that need, the good or service must be obtained at another location. Interaction may occur as a result.
The implications of all this for city landscapes should be clear. There are a great many different kinds of activities in a relatively small area. Some functions tend to cluster together, while others are scattered across the urban region. Since a variety of activities are carried on in a city, interaction is stimulated between functions or within zones of the same function. When the activities are mapped, the result is a greatly mixed pattern of land use.
The concentration of population and urban activities requires supporting functions as well. Traditionally organized and operated as various branches of city government, these public service functions are only indirectly productive in an economic sense, but they are necessary for commerce and industry.
In addition to such services as water, electricity, and sewage and garbage collection, cities provide police and fire protection, construction and maintenance of public movement facilities, health care, documentation of vital population statistics, and educational facilities, among others.
So pervasive did these services become in large cities that immense governmental structures developed to administer them. In the New York metropolitan region, to take the extreme case, more than 1,550 administrative agencies were in operation in 1982.
Yet another major component of the urban landscape is its level of accessibility. Easy access between most sections of an urban area has not always been a dominant consideration in city organization and structure. The original street plans of most cities in Megalopolis, for example, followed the simple square or rectangular grid pattern popular in the 17th and 18th centuries.
As these cities grew, the inadequate access provided by this street system became apparent. A square grid, for example, possesses frequent, right-angle intersections. Because the traffic flow is interrupted at each intersection, a greater traffic volume leads to longer pauses at each intersection. By 1900, Baltimore and Boston had each exceeded populations of 500,000, Philadelphia had reached nearly 1.3 million, and New York was approaching 3.5 million. The main impact of the automobile was then still in the future, but serious congestion was already present in these cities' centers.
Beginning in the 1950s, changes occurred that led to the rapid areal expansion of cities and the increased use of automobiles for travel. An increasing proportion of the work force in the cities began to live at distances and in residential densities that made it uneconomical for mass transit to reach them. Economically, the speed and flexibility of truck transport accelerated the diversion of short-haul freight from rail to road carriers. Traffic planners responded by recommending construction of peripheral circumferential, or ring, highways and high-volume, limited-access expressways to separate local movement from cross-town and through traffic. Partly successful, these changes, plus others, also increased demand for access within the city center, between the center and the periphery, and eventually between sections of the periphery. The entire pattern of accessibility became more complex and difficult to manage.
All of this accentuates another component of the urban landscape. This is a landscape of change. Tens of thousands of new residents enter a large city like Philadelphia or New York each year. Even greater numbers have been leaving, some to distant cities and some only into the metropolitan fringes. Structures are destroyed, new ones built. Street patterns are altered, the pattern of functions is changed, and flows of people, goods, and ideas are shifted to fit these new patterns.
Such changes may be observed in any major region in America, but, in some ways, they created Megalopolis.
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