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Urban rhythms and travel behaviour: Spatial and temporal phenomena of daily travel
PUBLICATIONS IN REVIEW This Department publishes reviews of recent publications in or related to the study of tourism. Individuals interested in submitting review essays and book reveiws should write directly to the Associate Editor for Publications in Review, Stephen Smith . Unsolicited reviews will not be accepted.
BOOK REVIEWS Annals of Tourism Research, Vol. 38, No. 2, pp. 723–725, 2011 Printed in Great Britain
www.elsevier.com/locate/atoures
URBAN RHYTHMS AND TRAVEL BEHAVIOUR: SPATIAL AND TEMPORAL PHENOMENA OF DAILY TRAVEL By Stefan Scho¨nfelder and Kay W. Axhausen. Ashgate 2010, xvii + 230 pp. (figures, tables, appendix, bibliography, index) US$ 99.95 Hbk. ISBN 978-0-7546-7515-0 Serena Volo Free University of Bozen-Bolzano, Italy Anyone who appreciates careful attention to methodological detail will appreciate this treatise on the measurement and analysis of the spatial and temporal travel patterns of daily human activities. In their modeling of intrapersonal activity demand patterns, Scho¨nfelder and Axhausen take a broad interpretation of patterns to include not just the space and time dimensions of travel, but also motivations. Their activity-based analysis of human mobility sheds a light on a complex phenomenon, and while there are minor aspects of some of their assumptions and conclusions with which one might quibble, their contribution is so significant as to dwarf any such objection. The authors present their methodological approach, statistical analysis, and conclusions in a very readable, concise, and systematically presented style. The authors begin with a theoretical discussion that is followed with definitions of key constructs and variables that serve as an effective lead-in to an overview of time, space, and travel analysis. The authors then describe the datasets upon which their analyses are based, three of which include GPS measurement of physical movements, and all of which are of recognized validity and quality. Any reader who makes
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Publications in review / Annals of Tourism Research 38 (2011) 723–743
the investment of a careful reading of the methodological foundations will be treated to a most interesting and revealing modeling of people’s daily travel behavior, their destination choices, and their ‘‘activity spaces’’, even if some of the mathematics may be moderately inaccessible to some readers. Lest the reader be inclined to question the practical relevance and significance of the authors’ topic and their analysis, their conclusions convincingly establish the significance of their findings to both transport and human geography research as well as to public policy and planning. The relevance to tourism science, though not made explicit, is also clear. The authors state early on that one microeconomic assumption made explicit in most travel research—viz., more travel will be undertaken when the generalized cost of travel falls—but raise the knotty problem that travel is interpreted and measured in different ways and that the different dimensions of travel are not perfectly correlated, thus creating a minor methodological and theoretical dilemma. They adopt the hypothesis that ‘‘travelers trade off the generalized cost of travel with the generalized cost of the activities undertaken’’ (p. 7). The construct of generalized costs, which they define as ‘‘the risk- and comfort-adjusted weighted sum of time spent on travel or activity’’ (p. 7), includes not only time and expenditures but also the social content of such activities and its contribution to social capital. Again, it may be possible to quibble with some of the author’s microeconomic assumptions given some recent research in behavioral economics, but the fact that they have recognized and accounted for the full range of tangible and intangible costs and benefits of travel in their modeling provides, at minimum, a very good first approximation of a model of daily travel behavior with good predictive validity and even a theoretical basis for its explanation. It will be instructive to keep in mind the datasets upon which the analyses and conclusions are based in interpreting both the praise and the criticism of the book. Seven different datasets, mostly longitudinal data, representing widely varying geographical locations, time frames, data collection methodologies, and data elements were included in the study. It is a credit to the authors that they were able to effectively integrate these diverse data sets into a single, focused analysis but a challenge to their conclusions that accrue from the lack of data commonality, despite an effective, if not heroic, effort to both describe for the reader the lack of commonality and its implications and an equally effective effort to account for it in their choice of analyses and strategies for data integration. The authors make a point of emphasizing the fact that theirs is an analysis of the dynamic aspects of daily travel, and their choice of mostly longitudinal data sets serves this claim very well as does their choice of analytic strategies. Their approach to measuring activity spaces is very effective even if these spaces are necessarily constrained by the time frame of the longitudinal data. So not surprisingly, their analytic strategies for describing the ‘‘where’’ and ‘‘when’’ dimensions of daily travel are more successful than their strategies for describing the ‘‘why’’ dimension. Their analysis of motives of travel is complicated by the fact that the social capital aspects of travel must be inferred from the travel activity though it cannot reliably reveal a traveler’s motivation for the destination choice. While most of the data analysis focuses on the space and time dimensions of daily travel, the authors are, by their own admission and to their credit, more interested in the motivational dimension: ‘‘trip making needs to be understood as a derived demand (p. 29)’’. However, to the extent that information (in the technical sense—i.e., uncertainty and its resolution) is one main raw material for choice making, the time frame during which the data were collected would seem to dilute somewhat the validity of the results to current times. The growth in the types of digital devices and communication capabilities available, the number of people who have access to them, and their wide range of uses (work, education, entertainment, household chores such as shopping, online banking, and information gath-
Publications in review / Annals of Tourism Research 38 (2011) 723–743
725
ering, such as traffic cameras) has greatly expanded since the data on which the study is based were collected. This modification of the supply structure of activity-space opportunities is likely to have changed the daily travel behavior of a significant percentage of the population and should lead to a rethinking of individuals’ personal worlds and to a re-interpretation of their multi-day rhythms and variety-seeking behavior. Most of the conclusions and implications drawn from the study are, at least by the time the reader encounters them, either not surprising—for example, dayto-day travel is partially shaped by routine, variety seeking and the will to minimize generalized costs—or are speculative—for example, the possibilities for effecting environmentally sensitive travel behavior. While these conclusions and implication are clearly warranted, their significance is dwarfed by the very significant methodological contribution the book makes to the study of travel behavior. Serena Volo: Competence Centre in Tourism Management and Tourism Economics (TOMTE), School of Economics and Management, Free University of BolzanoBozen, Bolzano 39100, Italy. Email Assigned 21 June 2010. Submitted October 13 2010. Accepted 21 December 2010. doi:10.1016/j.annals.2011.12.009
Annals of Tourism Research, Vol. 38, No. 2, pp. 725–727, 2011 Printed in Great Britain
VALUES IN TOURISM: AN ITINERARY TO TOURISM ETHICS By Sietske Gras-Dijkstra. ToerBoek/Edu’ Actief
BOOK REVIEWS Annals of Tourism Research, Vol. 38, No. 2, pp. 723–725, 2011 Printed in Great Britain
www.elsevier.com/locate/atoures
URBAN RHYTHMS AND TRAVEL BEHAVIOUR: SPATIAL AND TEMPORAL PHENOMENA OF DAILY TRAVEL By Stefan Scho¨nfelder and Kay W. Axhausen. Ashgate
723
724
Publications in review / Annals of Tourism Research 38 (2011) 723–743
the investment of a careful reading of the methodological foundations will be treated to a most interesting and revealing modeling of people’s daily travel behavior, their destination choices, and their ‘‘activity spaces’’, even if some of the mathematics may be moderately inaccessible to some readers. Lest the reader be inclined to question the practical relevance and significance of the authors’ topic and their analysis, their conclusions convincingly establish the significance of their findings to both transport and human geography research as well as to public policy and planning. The relevance to tourism science, though not made explicit, is also clear. The authors state early on that one microeconomic assumption made explicit in most travel research—viz., more travel will be undertaken when the generalized cost of travel falls—but raise the knotty problem that travel is interpreted and measured in different ways and that the different dimensions of travel are not perfectly correlated, thus creating a minor methodological and theoretical dilemma. They adopt the hypothesis that ‘‘travelers trade off the generalized cost of travel with the generalized cost of the activities undertaken’’ (p. 7). The construct of generalized costs, which they define as ‘‘the risk- and comfort-adjusted weighted sum of time spent on travel or activity’’ (p. 7), includes not only time and expenditures but also the social content of such activities and its contribution to social capital. Again, it may be possible to quibble with some of the author’s microeconomic assumptions given some recent research in behavioral economics, but the fact that they have recognized and accounted for the full range of tangible and intangible costs and benefits of travel in their modeling provides, at minimum, a very good first approximation of a model of daily travel behavior with good predictive validity and even a theoretical basis for its explanation. It will be instructive to keep in mind the datasets upon which the analyses and conclusions are based in interpreting both the praise and the criticism of the book. Seven different datasets, mostly longitudinal data, representing widely varying geographical locations, time frames, data collection methodologies, and data elements were included in the study. It is a credit to the authors that they were able to effectively integrate these diverse data sets into a single, focused analysis but a challenge to their conclusions that accrue from the lack of data commonality, despite an effective, if not heroic, effort to both describe for the reader the lack of commonality and its implications and an equally effective effort to account for it in their choice of analyses and strategies for data integration. The authors make a point of emphasizing the fact that theirs is an analysis of the dynamic aspects of daily travel, and their choice of mostly longitudinal data sets serves this claim very well as does their choice of analytic strategies. Their approach to measuring activity spaces is very effective even if these spaces are necessarily constrained by the time frame of the longitudinal data. So not surprisingly, their analytic strategies for describing the ‘‘where’’ and ‘‘when’’ dimensions of daily travel are more successful than their strategies for describing the ‘‘why’’ dimension. Their analysis of motives of travel is complicated by the fact that the social capital aspects of travel must be inferred from the travel activity though it cannot reliably reveal a traveler’s motivation for the destination choice. While most of the data analysis focuses on the space and time dimensions of daily travel, the authors are, by their own admission and to their credit, more interested in the motivational dimension: ‘‘trip making needs to be understood as a derived demand (p. 29)’’. However, to the extent that information (in the technical sense—i.e., uncertainty and its resolution) is one main raw material for choice making, the time frame during which the data were collected would seem to dilute somewhat the validity of the results to current times. The growth in the types of digital devices and communication capabilities available, the number of people who have access to them, and their wide range of uses (work, education, entertainment, household chores such as shopping, online banking, and information gath-
Publications in review / Annals of Tourism Research 38 (2011) 723–743
725
ering, such as traffic cameras) has greatly expanded since the data on which the study is based were collected. This modification of the supply structure of activity-space opportunities is likely to have changed the daily travel behavior of a significant percentage of the population and should lead to a rethinking of individuals’ personal worlds and to a re-interpretation of their multi-day rhythms and variety-seeking behavior. Most of the conclusions and implications drawn from the study are, at least by the time the reader encounters them, either not surprising—for example, dayto-day travel is partially shaped by routine, variety seeking and the will to minimize generalized costs—or are speculative—for example, the possibilities for effecting environmentally sensitive travel behavior. While these conclusions and implication are clearly warranted, their significance is dwarfed by the very significant methodological contribution the book makes to the study of travel behavior. Serena Volo: Competence Centre in Tourism Management and Tourism Economics (TOMTE), School of Economics and Management, Free University of BolzanoBozen, Bolzano 39100, Italy. Email
Annals of Tourism Research, Vol. 38, No. 2, pp. 725–727, 2011 Printed in Great Britain
VALUES IN TOURISM: AN ITINERARY TO TOURISM ETHICS By Sietske Gras-Dijkstra. ToerBoek/Edu’ Actief