Elizabeth K. Burns
Current empirical work on automobile dependence, gender and inner-city residence, and travel demand management offers insights into this conference's agenda of spatial technologies, geographic information, and the city. Geographic information systems (GIS), as one spatial technology, are now in common use in numerous urban public agencies to monitor, evaluate, and develop diverse policies and programs. While these GIS efforts have been put in place as an enabling technology, the activities supported by these efforts have tangible connections with travel and communications technologies. These GIS efforts allow monitoring, evaluation, and development of changed urban accessibility. It is now possible to identify intended and unintended consequences for different geographically- and socially-defined urban population groups.
Current urban transportation research addresses these issues in the empirical setting of low-density, automobile dependent cities of the American Southwest. In metropolitan Phoenix and Tucson, Arizona, growth in the labor force and number of daily trips exceeds the rapid population growth. Involuntary mobility describes the actual situation where travel is required between separate land uses. Access to a vehicle, as driver or passenger, is a prerequisite for participation in the labor force. These cities have pressing air quality problems, in large part as a result of vehicle travel, that are being addressed by various transportation system management and travel demand management efforts. Implications of spatial technologies for specific geographically- and socially-defined groups are just now being identified in these cities. Study of employment location of and travel by inner-city, low-income residents complements recent study of commute trip behavior in terms of mode of travel, distance, and time of employed women and men with similar marital and child-raising status.
This set of urban economic, social, and environmental issues is being addressed through spatial monitoring and analysis. These empirical research activities are described below with discussion of their possible extension. These initiatives can lead to wider applications of the geographic information sciences through expanded spatial analysis and modeling for more informed future decision making.
1. Urban accessibility
a. Empirical evidence. Changed urban accessibility merits direct study with originally designed data collection and analysis approaches. At present, however, there are often agency funding constraints. This study is also not always a high priority with key research agencies. There are, however, at least indirect ways to identify some of the widely conjectured changes in urban accessibility brought about by the increasingly widespread use of communication and information technologies. Urban public agencies already collect useful data for their own purposes that can partially identify these impacts.
It is possible to obtain employer and employee survey data collected by urban travel demand management agencies as public records, while recognizing some limitations on the data. Only selected populations may be studied, surveys may not be under the researcherís control, and there may be required limitations on reporting of individual results. For example, the substitution of actual commute trips by working at home or telecommuting from home or another site is monitored by annual employee surveys conducted at individual private companies as part of metropolitan travel reduction programs whose public purpose is reduction of urban travel for air quality and congestion mitigation benefits. The Maricopa County Regional Trip Reduction Program makes data on metropolitan Phoenix available under these conditions. Knowing whether telecommuting leads to additional non-work trips on telecommute days is not be known directly from an annual employee survey, however, and requires other data collection approaches such as daily activity diaries.
b. Urban land use and structure. Ideally, the impact of new spatial technologies should be monitored over time at different scales as precise as individual building and travel facility locations and extending to urban neighborhoods, districts and communities.
An incremental approach involves teasing out these impacts from existing data sources while demonstrating the value of more focused research. Companies that participate in travel demand management programs are identified by Standard Industrial Classification code and have an employee profile identifying occupation, travel behavior and demographic characteristics. These companies annually monitor individual work sites to identify compliance with trip reduction goals such as increased passengers per vehicle or reductions in miles traveled.
Travel behavior and employer policies at individual work sites can be aggregated to provide ongoing evidence of the spatial distribution of adoption of travel substitution in the form of telecommuting, adoption or lack-of-adoption by employees in particular occupations, and employee participation from distinct geographic- and socially-defined groups. Major employers with large single work sites, such as universities, airports, industrial and office parks, increasingly monitor and analyze travel using geographic information systems as part of regulated efforts and for their own marketing and management purposes (Burns, 1994; Burns, 1992).
c. Adaptation of land use and transportation models. Current large-scale land use and transportation models have been in place for the past thirty years and are increasingly questioned for lacking essential characteristics that reflect the substitutive, complementary, or synergistic effects of new spatial technologies. The traditional four-stage transportation model consists of trip generation, trip distribution, mode choice, and network assignment. High priorities for revision include: data on the length and timing of individual trips rather than aggregate link vehicle miles of travel, more accurate estimates of the spatial and temporal distributions of travel, increased data on the characteristics of the vehicle being used for particular trips, and information on freight as well as person travel (NCHRP, 1996). The author serves as a member of the national panel developing immediate, mid-range, and long-range procedures to be recommended for adoption by metropolitan planning agencies as improvements in land use and transportation models.
These improvements can provide more realism in understanding personal travel behavior choices. Travelers typically make decisions by considering time, place, cost, mode, route, in a context of required and discretionary daily activities. The standard four-step process treats these choices sequentially rather than simultaneously and usually without much sensitivity to the household or wider policy context. Indeed, a more regional and multi-scale approach is being considered. Instead of considering air quality and emissions from land use activities as dependent on transportation access, the future approach reverses this sequence. Urban air quality should be addressed first at a regional scale. The spatial and temporal distribution of emissions then results from specific activities and events. Finally, transportation and land use models describe and model current and future spatial growth patterns and accessibility with feedback to urban emissions and regional air quality.
2. Impact on populations
a. Empirical evidence. Large data sets of annual employee travel surveys provide a current resource to understand some impacts of access to new spatial technologies on specific geographically- and socially-defined groups. The following examples illustrate this approach for two groups of continuing interest to geographers and planners: inner-city residents and employed women. Inner-city residents are thought to be disadvantaged by the broad shift of employment from central cities to suburban locations over the past thirty years. This spatial mismatch is especially acute for low-income inner-city residents who are black or Hispanic, with low levels of education. Industrial jobs have left and residents are not qualified for new service and other central city jobs. Using 1995 employee and employer data for inner-city Phoenix, Burns and Gober (1996) identified the percentage of inner-city residents that 181 major inner-city employers hire. Of the 49,000 employees, 14% live in inner-city zip codes. This match was identified using a geographic information systems package, MapInfo, to identify employer locations and to address match employee work and residence locations by zip code.
Above-average levels of inner-city employment were manufacturing/production workers (36%) and skilled crafts and trade workers (18%), while only 7% of the professional/managerial workers live in inner-city zip codes. Inner-city employers with the largest proportion of inner-city workers are those in personal services (53%), agriculture (42%), hotels and other lodging (33%), retail trade (32%). While public administration provides 40% of jobs in this survey, City of Phoenix inner-city employment was just above average (16%), and state employment was only 9%. Industrial categories that employ a relatively small number of inner-city residents are communications and public utilities (5%), finance, insurance, and real estate (7%), transportation and material moving activities (8%), and other professional services, including legal and social services (11%).
This research illustrates some issues on changed conditions of access to employment, use of innovative transportation technologies, and public service delivery. This research is being conducted as part of a joint City of Phoenix, Arizona State University, U.S. Housing and Urban Development Community Outreach Center Partnership. At this time, City of Phoenix and Maricopa County staff are considering sharing the academic analysis of employer and employee data with individual employers whose labor force matches the skills of nearby inner-city residents. The advanced spatial technology in use here is descriptive geographic laborsheds for inner-city employers, while the potential is for detailed policy efforts with individual employers with specific labor needs. This approach is politically sensitive, however. Both City and County staff are cautious about approaching private employers who now hire below-average percentages of inner-city residents. This approach, however, is considered the most effective for both City job training efforts and County trip reduction activities.
Employed women provide a second case study. The lower average earnings of women in all occupational groups has led to a traditional interpretation of womenís travel as constrained by income. Women, on the whole, remain responsible for household errands and child- and elder-care. Therefore, women are expected to live closer to home than men, to use travel modes of low cost (bus), and to be more willing to work at home (telecommute). Recent findings by Rosenbloom and Burns (1995) emphasize that employed women in metropolitan Phoenix and Tucson are more dependent on driving to work than men of similar occupational, marital and family status. County surveys included a demographic questionnaire for 1990 and 1991 at Arizona State University and the University of Arizona with a minimum of 2,500 respondents on each campus. Women are more likely than men to drive alone or carpool, equally likely to use the bus, and less likely to walk, bike or use another mode, including telecommuting. Although unmarried people generally are more likely to drive alone than those who are married, women are always more likely to drive alone to work regardless of marital status. Having children tends to increase the likelihood that both men and women will drive alone. Employed women with young children (0 to 12 years) are the most likely to drive alone. This mode choice holds true even when employed women and men of similar household income are compared (Rosenbloom and Burns, 1993).
This research illustrates other insights into changed access to employment, use of advanced spatial technologies to substitute communication for travel, and issues of who actually conducts daily activities. This research shows that working women retain responsibilities for obtaining household services, child care, and emergencies. This demographic and domestic context for travel decisions means that the availability of new spatial technologies, such as telecommuting, is not enough to ensure their adoption by all potential participants. Women drive to work so that they can conduct before- and after-work and mid-day errands and have a car available for child-care emergencies. Working women in metropolitan Phoenix and Tucson were less responsive than men to travel demand measures initiated from 1990 to 1991.
3. Geographic information.
This research suggests some ways to capture changing notions of distance and access. Subjective concepts of distance and access play a role in creating barriers based on perceptions, such as an inner-city employerís unwillingness to hire inner-city residents. Inner-city residents could benefit from a GIS application matching employment locations by schedule and occupation, residential origins of current and potential employees, and current and needed transit routes.
Needed data sets will be collected by local, regional, state, and federal public agencies for their own purposes and supplemented by additional, focused surveys for specific purposes (demographic variables, specific occupational types of employers). The disadvantage of not having control over data collection and preparation is offset for academic researchers by the benefit of agencyís expenditures for data collection and preparation.
While there is great potential to integrate disparate travel reduction data sets and other sources of spatial data, not all agencies are ready to share data or to adopt common standards. Within the field of urban transportation in one metropolitan area, my experience suggests that it is difficult to get City and County agencies to recognize the mutual benefit of sharing data which will serve multiple public purposes. It is important to note, however, that academic researchers can be the catalyst for identifying these potential benefits. These benefits are of significant interest to national funding agencies.
Current uses of GIS in urban planning and transportation, policy making and management are just starting to address the full implications of urban access. Full use is not being made of the data now being collected. Travel reduction agencies have a wealth of information on employee residential location, gender, occupation, schedule, and travel behavior. Traditional modeling still relies on aggregate flow analysis, however. Non-profit groups, such as community and environmental activists in inner-city neighborhoods, and private employers are likely allies in developing and sustaining geographic information efforts when these efforts are linked to their own goals.
References
Burns, E. K., 1992, ìVanceís Commuting Analysis: An Application in Tempe, Arizona.î Yearbook of the Association of Pacific Coast Geographers, 54: 77-96.
Burns, E. K., 1994, ìLinking Geographic Information Systems and Trip Reduction Limitations in a Pilot Application.î Journal of Planning Education and Research, 13: 208-215.
Burns, E. K. and P. Gober, March 18, 1996, ìJob Linkages Among Inner-City Employers and Employees.î Draft paper, Department of Geography, Arizona State University.
Cambridge Systematics, Inc., 1996, ìTask 3: Analysis Framework: Quantifying Air Quality and Other Benefits and Costs of Transportation Control Measures.î Washington, DC: National Cooperative Highway Research Program Project 8-33, NationAcademy of Sciences.
Rosenbloom, S. and E. K. Burns, 1993, ìGender Differences in Commuter Travel in Tucson: Implications for Travel Demand Management Programs.î Transportation Research Record, No. 1404: 82-90.
Rosenbloom, S. and E. K. Burns, 1995, ìWhy Working Women Drive Alone: The Implications for Travel Reduction Programs.î Transportation Research Record, No. 1459: 39-45.
Elizabeth K. Burns is Professor of Geography and Director of the Center for Advanced Transportation Systems Research at Arizona State University. She received her Ph.D. in Geography from the University of California, Berkeley, in 1974 and is a member of the American Institute of Certified Planners. Her research interests include urban travel demand, growth management, and urban applications of geographic information systems. She directs the 1995-1997 Arizona State University Provostís Multidisciplinary Initiative on ìGeographic Information Systems: The Application of Computer Technology in the Southwestern Environment.
Marie Levie Administrative Assistant___________(602) 965-2001 Center for Advanced Transportation Systems Research