IDEAS home Printed from https://ideas.repec.org/p/cdl/itsrrp/qt9c3330tt.html
   My bibliography  Save this paper

The Ethical Challenges and Professional Responses of Travel Demand Forecasters

Author

Listed:
  • Brinkman, Anthony P.

Abstract

Thirty years ago scholars first presented convincing evidence that local officials use biased travel demand forecasts to justify decisions based on unstated considerations. Since then, a number of researchers have demonstrated convincingly that such forecasts are systematically optimistic-often wildly so-for reasons that cannot be explained solely by the inherent difficulty of predicting the future. Why do modelers-professional engineers and planners who use quantitative techniques to predict future demand for travel and estimate its potential impact on built and proposed transportation facilities-generate biased forecasts and otherwise tolerate the misuse of their work? On initial consideration, it is tempting to surmise that corrupt modelers are responsible for biased forecasting. Indeed, corruption is the most common explanation of forecasting bias and tales of mercenary behavior are all too common in the field. Data from in-depth interviews with twenty-nine travel demand forecasters throughout the United States and Canada, how-ever, suggest new and different ways to understand the suspect behavior of transportation planning professionals. Those most likely to introduce bias and invite misuse of travel forecasts assume that their technical analyses have little, if any, impact on policy making. For many, this leads to disillusionment and requires responses to cope with feelings of marginalization. Others, untroubled by their apparent lack of influence, are complacent and need ways to avoid the ethical questions of practice. Both types of practitioners circumscribe professional roles and rely on the self-deceptive strategies of evasion and excuse making to mute their own disquieting realities that undermine positive concepts of self. The disillusioned wish not to see that they do not matter and the complacent that they do. Bias and misuse seem to be the unintentional byproducts of these attitudes. Beyond enhancing the understanding of the systemic failures of travel demand modeling, this research suggests practicable steps to reform and outlines an agenda for future work. Attention to these matters is important, not just to avoid expenditures on projects and programs that cannot be justified on the basis of sound utilitarian calculations, but also to restore and preserve the credibility of a profession.

Suggested Citation

  • Brinkman, Anthony P., 2003. "The Ethical Challenges and Professional Responses of Travel Demand Forecasters," Institute of Transportation Studies, Research Reports, Working Papers, Proceedings qt9c3330tt, Institute of Transportation Studies, UC Berkeley.
  • Handle: RePEc:cdl:itsrrp:qt9c3330tt
    as

    Download full text from publisher

    File URL: https://www.escholarship.org/uc/item/9c3330tt.pdf;origin=repeccitec
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Skamris, Mette K. & Flyvbjerg, Bent, 1997. "Inaccuracy of traffic forecasts and cost estimates on large transport projects," Transport Policy, Elsevier, vol. 4(3), pages 141-146, July.
    2. Mackie, Peter & Preston, John, 1998. "Twenty-one sources of error and bias in transport project appraisal," Transport Policy, Elsevier, vol. 5(1), pages 1-7, January.
    3. Edwards, Marion & Mackett, Roger L, 1996. "Developing new urban public transport systems : An irrational decision-making process," Transport Policy, Elsevier, vol. 3(4), pages 225-239, October.
    4. Roy T. Meyers, 1996. "If policy analysts are depressed, what should they do about it?," Journal of Policy Analysis and Management, John Wiley & Sons, Ltd., vol. 15(3), pages 438-443.
    5. Nelson, Robert H, 1987. "The Economics Profession and the Making of Public Policy," Journal of Economic Literature, American Economic Association, vol. 25(1), pages 49-91, March.
    6. Flyvbjerg,Bent & Bruzelius,Nils & Rothengatter,Werner, 2003. "Megaprojects and Risk," Cambridge Books, Cambridge University Press, number 9780521009461, October.
    7. Tore Langmyhr, 2000. "The Rhetorical Side of Transport Planning," European Planning Studies, Taylor & Francis Journals, vol. 8(5), pages 669-684, October.
    8. Mackett, Roger L. & Edwards, Marion, 1998. "The impact of new urban public transport systems: will the expectations be met?," Transportation Research Part A: Policy and Practice, Elsevier, vol. 32(4), pages 231-245, May.
    9. Small, K. & Winston, C., 1998. ""The Demand for Transportation: Models and Applications"," Papers 98-99-6, California Irvine - School of Social Sciences.
    10. Rubin, Thomas A. & Moore II, James E. & Lee, Shin, 1999. "Ten myths about US urban rail systems," Transport Policy, Elsevier, vol. 6(1), pages 57-73, January.
    11. Goetz, Andrew R. & Szyliowicz, Joseph S., 1997. "Revisiting transportation planning and decision making theory: The case of Denver International Airport," Transportation Research Part A: Policy and Practice, Elsevier, vol. 31(4), pages 263-280, July.
    12. Kenneth Button & Roger R. Stough (ed.), 0. "Transport Policy," Books, Edward Elgar Publishing, number 1405.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Tal, Gil & Cohen-Blankshtain, Galit, 2011. "Understanding the role of the forecast-maker in overestimation forecasts of policy impacts: The case of Travel Demand Management policies," Transportation Research Part A: Policy and Practice, Elsevier, vol. 45(5), pages 389-400, June.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Brinkman, P. Anthony, 2003. "The Ethical Challenges and Professional Responses of Travel Demand Forecasters," University of California Transportation Center, Working Papers qt7vb2d17h, University of California Transportation Center.
    2. Brinkman, P. Anthony, 2003. "The Ethical Challenges and Professional Responses of Travel Demand Forecasters," University of California Transportation Center, Working Papers qt6dv0z95g, University of California Transportation Center.
    3. Bent Flyvbjerg, 2006. "Cost Overruns and Demand Shortfalls in Urban Rail and Other Infrastructure," Transportation Planning and Technology, Taylor & Francis Journals, vol. 30(1), pages 9-30, February.
    4. Hensher, David A., 2007. "Bus transport: Economics, policy and planning," Research in Transportation Economics, Elsevier, vol. 18(1), pages 1-507, January.
    5. Bradley Lane, 2011. "TAZ-level variation in work trip mode choice between 1990 and 2000 and the presence of rail transit," Journal of Geographical Systems, Springer, vol. 13(2), pages 147-171, June.
    6. Lane, Bradley W., 2008. "Significant characteristics of the urban rail renaissance in the United States: A discriminant analysis," Transportation Research Part A: Policy and Practice, Elsevier, vol. 42(2), pages 279-295, February.
    7. De Bruijn, Hans & Veeneman, Wijnand, 2009. "Decision-making for light rail," Transportation Research Part A: Policy and Practice, Elsevier, vol. 43(4), pages 349-359, May.
    8. Cantarelli, C.C. & Molin, E.J.E. & van Wee, B. & Flyvbjerg, B., 2012. "Characteristics of cost overruns for Dutch transport infrastructure projects and the importance of the decision to build and project phases," Transport Policy, Elsevier, vol. 22(C), pages 49-56.
    9. Thomopoulos, N. & Grant-Muller, S. & Tight, M.R., 2009. "Incorporating equity considerations in transport infrastructure evaluation: Current practice and a proposed methodology," Evaluation and Program Planning, Elsevier, vol. 32(4), pages 351-359, November.
    10. Verweij, Stefan & van Meerkerk, Ingmar & Korthagen, Iris A., 2015. "Reasons for contract changes in implementing Dutch transportation infrastructure projects: An empirical exploration," Transport Policy, Elsevier, vol. 37(C), pages 195-202.
    11. Petter Osmundsen & Kristin Helen Roll, 2016. "Rig Rates and Drilling Speed: Reinforcing Effects," CESifo Working Paper Series 5895, CESifo.
    12. Tal, Gil & Cohen-Blankshtain, Galit, 2011. "Understanding the role of the forecast-maker in overestimation forecasts of policy impacts: The case of Travel Demand Management policies," Transportation Research Part A: Policy and Practice, Elsevier, vol. 45(5), pages 389-400, June.
    13. Dimitriou, Harry T. & Ward, E. John & Dean, Marco, 2016. "Presenting the case for the application of multi-criteria analysis to mega transport infrastructure project appraisal," Research in Transportation Economics, Elsevier, vol. 58(C), pages 7-20.
    14. Alpkokin, Pelin & Ergun, Murat, 2012. "Istanbul Metrobüs: first intercontinental bus rapid transit," Journal of Transport Geography, Elsevier, vol. 24(C), pages 58-66.
    15. Athias, Laure & Nunez, Antonio, 2008. "The more the merrier? Number of bidders, information dispersion, renegotiation and winner’s curse in toll road concessions," MPRA Paper 10539, University Library of Munich, Germany.
    16. Zhou, You & Zhang, Lingzhu & Chiaradia, Alain J F, 2021. "An adaptation of reference class forecasting for the assessment of large-scale urban planning vision, a SEM-ANN approach to the case of Hong Kong Lantau tomorrow," Land Use Policy, Elsevier, vol. 109(C).
    17. Jorge Valido, 2020. "Large Infrastructure Investments: Financing Mechanisms and Incentives in Decentralised Countries," Fiscal Studies, John Wiley & Sons, vol. 41(4), pages 905-921, December.
    18. Galit Cohen-Blankshtain & Eran Feitelson, 2011. "Light rail routing: do goals matter?," Transportation, Springer, vol. 38(2), pages 343-361, March.
    19. Øglend, Atle & Osmundsen, Petter & Lorentzen, Sindre, 2016. "Cost Overrun at the Norwegian Continental Shelf: The element of surprise," UiS Working Papers in Economics and Finance 2016/3, University of Stavanger.
    20. Knowles, Richard D. & Matthiessen, Christian W., 2009. "Barrier effects of international borders on fixed link traffic generation: the case of Øresundsbron," Journal of Transport Geography, Elsevier, vol. 17(3), pages 155-165.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:cdl:itsrrp:qt9c3330tt. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Lisa Schiff (email available below). General contact details of provider: https://edirc.repec.org/data/itucbus.html .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.