Introduction
This is a difficult period for geographers and others whose concern is to figure out the effect of space and location on the city both for purposes of science and policy. Rapid although not unprecedented rates of change in communications technologies due to the long wave associated with the emergence of digital technologies in the mid-century, are forcing a dramatic restructuring of spatial relationships within urban areas as work and leisure respond to increasing productivity and opportunities for interaction across an expanding array of media. The emergence of world cities and edge cities is causing a fundamental reevaluation of traditional urban theory fashioned as it was on our observation and understanding, albeit rudimentary, of the industrial city. The fact that much of the new electronic media is comparatively invisible in its use and impact hinders traditional methods of observation and data collection while the speed of change is greater than our ability to record and make sense of this changing milieu.
In the last year, 20 percent of US adults have accessed the Internet through the world wide web and increasingly software associated with making this network more user friendly and accessible is becoming the cutting edge for desktop applications. For example, network browsers are being used for local networks but also for presentation devices while the growth of multimedia - animation and VR - through such software is proceeding apace. Talk of commerce moving to the web, of a multitude of traditional face to face transactions becoming remote, as well as the delivery of traditional public services from health to education, suggests as very different kind of urban form from the one that was associated with the rise of urban society and cities over the last 200 years. The implications seem daunting and the speculation and hyperbole (including my own !) is rife.
How Information Networks Can Affect Accessibility
It is easy to get caught up in the rhetoric but the impact of new information technologies on accessibility are ambiguous and uncharted, notwithstanding their pervasiveness. In essence, the argument is as follows: interacting across computer networks has the possibility of substituting physical communications for electronic with consequent impacts on movement in cities. Teleworking is the classic example but all forms of service delivery are potentially within the frame. The question is thus: to what extent are such substitutions likely to take place and what will be their impact on urban form. The limits to such a debate are clearly marked out in the story by E. M. Forster called RThe Machine StopsS which was published almost 100 years ago, in which he portrays the social isolation of such a world. In fact, from anecdotal evidence, it appears that electronic networks are in fact complementing and perhaps even increasing interaction, adding a new layer of complexity to urban society, rather than replacing or substituting for physical interactions.
What can probably now be said is that the impacts of networking are likely to be second rather than first order: not those of direct but of indirect substitution. For example, the largest changes in movement patterns in cities over the last twenty years are due to the purchase of second and third cars which have led to massive increases in tripmaking for education, leisure and shopping activities; changing perceptions and constraints on the use of time which have spread movement out during the day; increases in traffic congestion and related gridlock which in a European context at least is forcing people back into the city; dramatic declines in public transportation due to increasing car ownership but also changes in the way public activity is perceived and valued which in turn relates to the rise of individualism and the demise of socialism.
Historical Determinism
In my view, this meeting is about charting the limits to the debate, one which has only just begun and one which so far does not have any sense of an organized research programme within its grasp. Studies of previous revolutions in communication are thus warranted and it is here that the role of historical inertia - determinism if you will - becomes important. In urban societies highly constrained by limits on space and land, where people live at very high densities, the automobile has had a quite different impact from cities in the new world. It has been harder to provide the physical infrastructure and the classic examples of Redge citiesS are harder to find. Everywhere there have been significant changes in physical accessibility but these have been much more subtle than the traditional models of the spreading city might imply. The same is certainly true of electronic communications: the telephone is not perhaps a good example as this is clearly a highly passive device in terms of delivering services but electronic networks are also developing to add as well as replace routine functions of consumption and production. Like highways, network infrastructure develops in response to the dissemination of the vehicles - computers - which make electronic travel possible, and there are many predictions that global networks such as the Internet will have to be radically overhauled if they are to act to delver services such as commerce in anything other than an idiosyncratic fashion. In fact, it is much more likely that networks will be assembled at very scales for specific purposes, hence the current drift towards intranets rather than the Internet.
A recent poll in Business Week (August 26 1996) suggests that only around 7 percent of the population are likely to develop serious use of the Internet with the consequent implications that this media will have much less impact on physical service delivery in cities than might be supposed. And that this percentage will rise at a much slower rate than general usage of the net.
Geographic Information and Scale
The role of GIS and related technologies in this ferment is also anomalous. GIS enables geographic scientists to compose and synthesize information about the city more effectively. It enables the great streams of digital data which are emerging to be organized. And it enables designers, planners, and policy makers to use such data for more effective decision-making. But like many new information technologies, GIS is being quickly disseminated into highly routine decision-making. Just as Herbert Simon once argued that it was impossible to answer the question how management science changed management because it had and this had in turn changed management science, so it is increasingly difficult to see GIS technologies as standing apart from the very systems that GIS is designed to inform. In short, GIS is being used to study systems which increasingly function using GIS which is part of the general problem that we use computers and data to study systems which are composed of those same computers and data. GIS is thus becoming part of the information infrastructure.
In this context, it seems to me GIS will enable us to say something very significant about the role of scale in urban systems, primarily because it admits the possibility of being scale independent and thus offering an ability to understand the effect of scale at different levels. Of course the role of scale is being affected by the very technologies that we are working with but as I have argued above, this impact is uncertain and hard to disentangle from a myriad of other often correlated factors. In the development of postindustrial society, it is now very clear that local and global events coincide and interrelate in very subtle ways and that this in itself is a consequence of the changing role of scale. For example edge cities are easy enough to understand at the scale of the metropolis but world cities can only be understood globally and can only function using global networks. GIS has the ability to transcend scale.
Perhaps the most illuminating aspects of GIS and scale relate to the most local. With the development of property parcel information systems and address point data, very detailed effects of scale in urban areas can be explored systematically for the first time. Accessibility at the level of streets and city blocks for example, even within buildings and rooms have rarely been studied to date but it is clear that questions of crime and safety in cities, questions of transition and land values, of segregation and polarization must be explored at these levels. Anything coarser will simply miss the critical issues. In short, GIS is likely to give us an ability to develop theories and policies at much more local scales than we have been able to do effectively hitherto and to relate these to broader scales, thus enabling us to link micro to macro not just as another exercise in spatial aggregation but as a way of showing how physical form merges into social and economic activity for long the domain of human geographers. In my presentation, I will show some example as to what can be done with GIS at these more local scales.
Summary
I use this note simply to point up a series of ideas which doubtless will be widely discussed at the meeting but to also point to the disjunction between using GIS in traditional terms and studying the way GIS is becoming part of the very infrastructure that we choose to study. This seems to me to be the domain we have to chart and one whose limits we have to be clear about from this meeting.