David Lemberg
Jules Verne's Around the World in Eighty Days (1873) presents an allegory of spatial connectivity in the height of the Industrial Age. In the story, he shows through the journey of Phileas Fogg, a gentleman adventurer, that with knowledge, resources, and initiative, one could use the various transportation modes available to circle the world in 80 days (or in extension could travel from London to any part of the world within a couple of months). In 1872, the completion of a world-wide set of steamship and railroad links allowed Mr. Fogg to attempt and complete the journey equipped with just a set of maps, a packet of rail and steamship schedules, a British passport, and a carpet bag full of pound notes . The story also introduced to the Victorian Age the dawn of the Information Society. Perhaps was even more fantastic to the world of 1872 than the journey itself was the speed at which reports of the journey could be transmitted back to the newspapers (and wagerers) back in London. The new spatial technologies in 1872 were the undersea telegraph cables and fast mail-packet ships, which introduced the world to the fast, long distance communication that we now take for granted.
But how does all of this relate to spatial technologies, geographic information, and the city? While Verne did not explore changes in urban form, I would hold that his story of a shrinking world in the Industrial Age has many lessons for us in terms of connectivity and accessibility in human spaces, as we now experience another phase change in the Information Age. A hundred years after "Around the World in Eighty Days", I can not identify an equivalent work of literature that so well defines spatial connectivity in the Information Age. Spatial connectivity has changed enough that some sort of sequel is in order. We can now easily circle the globe in three days using regular air schedules (less than 24 hours in a Concorde). I won t try to convert ú30,000 in 1872 into 1996 dollars, but $2,500 should get you anywhere you need to go. The array of telecommunications available is even more impressive; voice and data transmission over surface and satellite connections allow one to communicate from and to any location on earth. In short, like Phileas Fogg, we all now have opportunity to become gentleman (gentleperson?) adventurers, able to travel to or communicate with any person or location on Earth given enough resources.
In theory, if we really do have the ability to travel to or communicate with any person or location on Earth, we could live anywhere we wanted to live. In reality, of course, we don t have unlimited resources, and in fact, resources vary widely by individuals, by groups, and by societies. I am operating under the hypothesis that our future urban form is going to be based on accessibility, much like the past urban forms have been determined by their transportation systems. The major question to be posed in this paper is how the concepts of accessibility and connectivity must expand to fit a world where more and more spatial interaction occurs over the telecommunications networks rather than the transportation networks. Telecommunications costs are becoming elastic over greater distances. With equal costs and equal time for one mile, ten miles, a hundred miles, and one thousand miles, many traditional aspects of spatial interaction in urban hierarchies such as distance decay, intervening opportunity, and activity spaces become less important, irrelevant, or distorted from the present norm. Accessibility and connectivity as determinants of human settlement patterns must reflect both linear and nonlinear network links.
Much of spatial and locational analysis is based upon functions of accessibility. Accessibility is defined in Johnston's Dictionary of Human Geography (1994) as "the ease by which one place may reached by another". Measures of accessibility include geodetic distance, topological distance, route distance, travel time, and travel cost. Accessibility may be applied between two sites or as a measure or index of a site to its situation, or may also be used to show the relationship between a location and some aspect of the space around the location (ie. accessibility to job opportunities). The transportation technologies available to the individual or group and the connections of the transportation network at each place also factor into the accessibility equation. As transportation techniques have improved and diffused from foot and wind oriented transportation, through steam and hydrocarbon driven transport, to copper and silicon based telecommunications, accessibility between places has improved.
Another component in the general definition of accessibility is the existence of barriers. These barriers may include socio-economic status (ie. one can not afford a car) or belief (the Pennsylvania Amish won't use cars or phones). In reality, there are not many true barriers, but many impedances to accessibility. An impedance is a resistance factor. An example of impedance is that while many urban dwellers can afford cars, traffic, parking, and other factors can make many of those people resistant to auto ownership. There are impedances to all modes of transportation and telecommunication. When impedances become very high (close to one), they become barriers.
The advent of telecommunications as a major factor in our activities and interaction creates a number of problems with the general model of accessibility. The general measures of accessibility : distance, time, and cost are irrelevant on the Internet. In real terms, if you hook into the Net, it is as easy, fast, and cheap to send e-mail to another continent as it is to send it next door. In a wired world, there are both real places where people live and time and space are constraints, and virtual places where people can come together without the constraints of space (time constraints are whether the parties are all simultaneously awake). So what is a modern definition of accessibility?
A modern definition of accessibility is not from place to place, but rather from a person or persons in a place to other persons and places. To develop an index of accessibility, one would need to define a set of activities and interactions for a person or group of people and tie each of those activities and interactions to various spatial and non-spatial (telecommunications-based) transportation technologies. Accessibility is a measure both of the ease of interaction between locations and a measure of the socio-demographic-cultural-behavioral aspects of the individuals or groups interacting. In order to develop new tools for site location, activity analysis, transportation analysis, etc., geographers need to include non-spatial transportation activity into measures of accessibility. One can not analyze the effects of spatial technologies on the disadvantaged in the center city and rural periphery without an understanding of the impedances and barriers to their use.
Accessibility is a multiobjective function. The accessibility of one location to another location is a weighted sum of spatial and non-spatial network accessibility factors. The spatial factors describe the connectivity and impedances in the surface transportation systems (roads, railroads, waterways, and air routes). All of these spatial networks are subject to the general rules of spatial interaction such as distance decay. Non-spatial factors describe the telecommunications links between places. While there are still some distance effects in telecommunications such as long distance toll calling, the costs of such tolls have been steadily dropping to the point where they may soon disappear or at least become so low as to be a minor factor. In terms of the gentleman adventurer on the global network, we can describe network accessibility as the combination of network connectivity (both spatial and non-spatial), knowledge, resources, and initiative.
Network connectivity may be physically represented by the network infrastructure. For the spatial network, this is the road, rail, water and air connections. These network connections are a major part of our current urban structure. Our future urban structure will continue to be strongly effected by these networks, especially by the system of airline hubs and local, regional, national, and international delivery systems. The airline connections will facilitate the decentralization or transfer of service and information processing locations, allowing fast face-to-face meetings where telecommunications will not suffice. An example of this trend is in the growth of the Salt Lake City metropolitan area around a combination of skilled labor and a worldwide airline hub (Wysocki, 1996). Improvements in the logistics of package delivery systems have created a fusion of spatial and nonspatial networks. The spatial component is the combination of public (Postal Service) and private (Federal Express, UPS, DHL, etc.) carriers that can cheaply and efficiently deliver packages same-day, overnight, or within a few days to any location. The nonspatial component of this network are the mail order (really phone order or net order) catalogue stores that use the delivery carrier network to provide all of the necessities and luxuries of life. This remote shopping system should facilitate exurban settlement, just as the Sears- Roebuck catalogue facilitated rural living a hundred years ago.
The non-spatial network infrastructure includes the line connections, the line speed, and the line capacity of the telecommunications network. This includes connections of copper wire, coaxial cable, and glass fiber, but can include non-linear cellular or satellite connections. With that network, speed and capacity impedances may limit the types and quality of the communication and information available. There are also carrier impedances. Are network connections worldwide, regional, or only local? What information mode impedances exist on the networks? What does one need to communicate, and how does one communicate? Is text, voice, graphics, or video, or some combination of modes required? Does the task need real-time interactive communication or is batch-mode communication sufficient?
We are now seeing the equivalent of the historic railroad wars among communities, with small towns in the Midwest lobbying and granting incentives for fiber optic lines instead of steel rails (Woutat, 1992). In terms of urban forms and competitive advantage, it is the suburban and exurban lands that have the advantage in telecommunications infrastructure. It is much more difficult to pull lines through old urban neighborhoods with antiquated housing, especially with lower indigenous demand for the services to drive the installation.
Knowledge is the second component of accessibility; both in knowing what is available and in knowing how to use what is available. Using our spatial transportation network provides few roadblocks - almost anyone can learn to drive. Our more complicated multimodal transportation and computer based telecommunications systems can present more barriers. They pose a number of problems, especially for the non-technically educated population in the center cities and rural backwaters. Can one learn to use the computers, terminals, user interfaces, etc., and conversely, can the service providers simplify net access so that computer literacy, or literacy in general is not required? What are the learning curves? How may the language barriers be overcome for non-English speakers and non-Jargon speakers?
Of perhaps greater concern is how the unskilled and low skilled ex-industrial workers may gain employable skills in the Information Economy. Telecommunications can aid in spatial mismatch problems only if there are jobs that can be done remotely. A problem more germane to geographers is how GIS technology may be used to represent and build multimodal trips and how the "geography of the net" may be presented in some meaningful way. In a GIS, these network connections can be represented as nodes and links. The nodes represent both the location and the connectivity impedances of individuals, groups, and places. The links represent the connectivity between nodes on the network and the weighted impedances of those links.
One can visualize many layers in the global network; one layer for each mode of transportation and telecommunication, and different layers for different carriers and cargo (ie. information, package delivery, bulk freight, etc.). Part of the knowledge required for full access to the "information highway" is a mental map of the virtual geography. Searching and indexing information on the Net can be a barrier. How does one find what is out there? In the spatial world, you can represent the entire space in one world map; in the virtual world, there is no such representation.
Resources, both financial and temporal, are the third component of accessibility. For the urban poor, resource constraints include computer terminal purchase costs, access charges, use charges, line extension and hookup costs, etc. There is also the question of time available - if one is working full time for subsistence wages, there is little time available to learn about new technologies. Phileas Fogg had independent means, but time constraints structured his entire existence. In modern times, our activity schedules constrain our interaction. In location decisions, our modern adventurer must balance his or her financial and temporal resources against their activity requirements and preferences. The task is to overlay the types of amenities, employment, and connections available at each location upon the costs, speed, and convenience of the various modes of spatial and nonspatial travel to fit one's activity schedule. Another interesting application of GIS could be to collect, process, and visualize some index of local accessibility, perhaps as a synthesis of activity spaces on a network (Miller, 1991) and spatial / nonspatial connectivity.
Initiative is the final component of accessibility. One must have the initiative to use what is available or to locate where one can maximize the mix of jobs, amenities, and lifestyle. Impedances to initiative can include religious, ethnic, cultural, or subcultural biases against mobility or against using or learning to use new technologies. The center city and rural peripheries concentrate many of the groups that hold to such biases against change, novelty, mobility, or education. There are also political constraints for some locations (mainly foreign) including travel restrictions, government censorship of information, government distortion of information, government monitoring of communications, and embargo of information goods, and services.
It is difficult to predict the impact of emerging technologies on urban patterns and socio- economic structures. As an example, Castells (1989) in "The Informational City" does a good job of extrapolating an Information Age society from the Reagan - Cold War era. The fall of the Iron Curtain and the subsequent de-emphasis of military expenditures made much of that analysis irrelevant. Based upon technological trends, possibilities in urban development include decentralization of urban functions, breakdown of urban hierarchies, emphasis on amenities for location decisions, loss of unskilled and low skilled jobs, and stratification of individuals, groups, and locations by access. Given these trends we will see (are seeing) the creation of Information Age relict populations in the urban centers and rural peripheries. If we propose public policies for mitigation of these problem populations based upon accessibility deficiencies, our priorities should be limited to applying resources to build connectivity (extending infrastructure) and to further education (in basic skills in telecommunications use and in job skills in an Information Economy), for without knowledge and connectivity, any other resource allocation (such as location subsidies or "a computer in every pot") will go for nought.
In conclusion, I would venture to say that there needs to be much more work on how this definition of the aspects of accessibility in the information age effects the future of urban structure. In particular, if we are to continue to use spatial models in generating and evaluating urban policy for site location, service districting, etc., we need to develop metrics for accessibility. I would explore this area in terms of my own work in group spatial decision support for urban planning. In order to collaboratively generate feasible policy alternatives, the parties and interest groups must agree on the objectives and constraints of the problems. While distance and travel time are easily measured, measures of accessibility are more subjective. From a practical standpoint, how could GIS be used to facilitate the measurement of accessibility in our urban neighborhoods? How could such a system overcome the barriers of language and literacy we face in collecting data in the urban cores of our cities? Could we use GIS as a tool to promote consensus between the neighborhoods and city hall on measures of current conditions so that the planning staff might be able to model future needs and solutions? Spatial technologies may be the driver of urban change in the information age, but could also be the key to developing the tools to manage the effects of those changes.
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