Friday, January 27, 2012

Getting outside that box (which may require being just a bit unreasonable)

Once we are cozily set up in our box -- a box of course that we can neither see nor really appreciate (What box?) -- we become accustomed to thinking of things comfortably wedged within our invisible container  as "that's the way things are".  And from there it is a very small step to become  a pragmatically "reasonable person".  To which I can only quote Bernard Shaw when he said so long ago (with social justice and the emancipation of women firmly in the middle of his sites): The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.  Let's see if Preston Schiller can help us to get outside the box of the automobile.

Getting outside the box of the automobile

- Preston L. Schiller

I propose that engineers who work in urban transportation get outside the box that most have enclosed themselves in for the past several decades. Literally. I propose getting out of the rectangular solid box of the automobile (or the more inclusive term PMV for private motor vehicle) within which much transportation engineering thinking is trapped. I propose a serious questioning of many of the premises guiding the ways that city streets, intended to be shared by many users for many purposes, have been transformed into roads dominated by one user, the PMV.

I believe it is time to review the trajectory that has turned this domain of engineering away from efficiency as a guiding ethic to promoting the multiple inefficiencies of the PMV; away from an ethic of safety for all to an ethic of safety for those inside a PMV; away from balance and equity to an overprivileging of one mode.

Mind you, I am not anti-engineer. I think it is vitally important for engineers to be the authorities on stresses, loads, structural capacties, relations between gradients, curves and velocities and similar phenomena. But I am troubled by the over-reach of the profession when it comes to that basically human phenomenon known as traffic; an area that can be influenced by the physical but involves numerous factors best addressed by the social sciences.

This field is much too complex for any one profession, and decision-making needs to be shared with planners, public policy experts, elected officials, psychologists, sociologists, anthropologists, economists and the public--especially those who have been traditionally neglected; those who walk, bicycle, have mobility issues, use transit and want safe streets for children and the elderly.

What happened to efficiency?

A memorable film of my 1950s childhood was “Cheaper by the dozen,” a biographical account of Frank B. Gilbreth, Sr., a pioneer in time and motion studies in the early twentieth century. The story is told by two of his dozen children. Many aspects of their household and family life were organized according to efficiency principles by Gilbreth Sr. who was generally considered a masterful mechanical engineer despite being self-educated and uncredentialed (Gilbreth and Carey, 1948). I grew up believing that engineering was all about efficiency and safety; increasing the ratio of outputs to inputs, making processes speedier and safer for those engaged in them.

Out of environmental concerns in mid-life I turned my attention to air pollution which led me to transportation as the much ignored elephant in that room. I discovered that the fuel efficiency of internal combustion engine vehicles was fifteen per cent, likely down to single digits were a complete life cycle analysis undertaken. If all the highly subsidized, unpriced and underpriced infrastructure and service provisions, from fuels and driveways to expressways to parking, planning, operations, maintenance, emergency response and enforcement were to be included I suspect that the fifteen per cent figure would quickly shrink well into negative territory. I came to think of PMV-based transportation as a “black hole” into which we poured endless resources, money and human lives and whose demands and wishes were impossible to satisfy. (Levinson, undated)

The ways in which transportation engineers assess the efficiency of roads and intersections also attracted my attention. It appears that the dominant engineering practice is to evaluate roads and intersections in terms of vehicle throughput versus delay. Keep the traffic moving at a brisk pace and if it slows then speed it up by expanding capacity or fiddling with the traffic signals—the extremity of which is satirically depicted in Figure 1, a sculpture erected to replace an old tree destroyed by motor vehicle pollution (Vivant 1998).

Perhaps a better measure would be person throughput? Or the amount of space and time a mode consumes for a trip? Or a combination of these two? In these cases the efficiency winners would be transit, walking and bicycling rather than simply vehicular throughput and it would only be fair and proper to give these modes priority; more space, more traffic signal time. (Bruun and Vuchic, 1996; Bruun and Schiller, 1996) Figure 2 indicates the much greater efficiency of walking, bicycling and transit compared to car-based commuting when time-area analysis is done (Bruun and Schiller 1996)

What happened to safety?

The engineers’ views on safety also attracted my attention as it seemed essentially to be measured in terms of reported traffic incidents and questionable standards and practices; more incidents created more points for interventions. Intersections qualified for an intervention after a certain number of traffic incidents were reported--severe crashes and deaths gained bonus points for an intervention. Urban streets qualified when the average speed was well above that posted or when too many motorists collided with trees in boulevard strips.

Curiously it often seemed that the cure for speeding was to raise the speed limit or remove the pedestrian protective trees and boulevard strips rather than slowing the speeders. Or the road was widened despite credible evidence that wider roads were less safe than more narrow ones. (Hauer, 2000; Pucher and Buehler, 2010) To the contrary, a growing amount of evidence pointed to narrower roads and “skinny streets” as safer than wider ones. (StreetsWiki, undated; Miller, 2009; Marohn, 2010) Occasionally the cure for a dangerous intersection was to forbid pedestrians from crossing there and directing them to another often uncomfortably distant intersection.

Especially curious was the reporting of crashes using a measure of vehicle kilometres travelled (vkt or vkmt) as the denominator; asserting that the situation of pedestrians and bicyclists was improving because fewer of them were being squashed per 100,000 vkt or vmt. (The National Academies, 2002; Richter et al, 2001) Or did these statistics mean that motorists were driving more? Or that motorists had to drive further to find a pedestrian or bicyclist target to squash since most were discouraged from walking and bicycling by the mounting levels of traffic and unsafe walking and cycling conditions?

Part of the problem is that road and intersection standards (Wellar, 2010) are not always correct or appropriate. Or they may be correct for rural or limited access/separated roadways but inappropriate for city streets and urban traffic. Drivers on city streets should be attentive, not relaxed. They should be alert for children running into the street, vehicles stopping or veering suddenly. Their caution should be reinforced with lower speed limits and streets designed to enforce slower speeds. Then all street users will be safer.

The old BAU paradigm hangs on

Despite its many shortcomings and lack of applicability to city streets and urban traffic the dominant paradigm of road expansion as the way to relieve congestion, smooth traffic flow and reduce emissions continued to dominate the field. Traffic was conceptualized as a liquid, and increased flow was accommodated by facility expansion, despite observations that traffic behaved more like a gas; as levels increased it became more dense and compressed and when some street space was reduced it often evaporated (Cairns et al, 2002; European Commission, undated; Litman, 2010). Free right turns and right turns on red were touted as ways of keeping traffic moving and reducing emissions. They were not (Newman et al,1988; Zador, 1984; Preusser et al, 2002).

Road expansions were observed to generate traffic unexpectedly stimulating new and longer trips (Noland, 2001; SACTRA, 1994; Litman, 2010), yet the highway expansion machine rolled on. Boulevard strips were eliminated to create more lanes, and stately trees shading sidewalks and houses and protecting pedestrians were removed as “obstacles” to more lanes or traffic or both (Dumbaugh, 2005; Wolf and Bratton, 2006). Instead of a widespread reflection upon and reconsideration of its mission and paradigm the profession continued on, with a few exceptions, with business as usual (BAU). But recent years have seen the more progressive and reflective elements of the profession articulating the need for a new paradigm.

A new paradigm of sustainable transportation

Fortunately a new paradigm of sustainable transportation is close at hand. My colleagues Eric Bruun and Jeff Kenworthy and I describe the new paradigm in our recently published book, An Introduction to Sustainable Transportation (Schiller et al, 2010, esp. Chapters 7 & 8). The new paradigm stresses several departures from BAU:
• accessibility, environment and equity trump increased PMV mobility--the number of significant destinations that are relatively close and can be reached by walking, bicycling or public transportation is stressed rather than the BAU approach of making any and all destinations available regardless of their environmental or equity consequences.
• mobility management (also known as transportation demand management or TDM) is stressed rather than reflex-like expansions of roads to meet motorists’ demands.
• multi-modalism and intermodalism; the provision of an array of transportation options as well as the improvement of connections between them is stressed.
• land use planning that supports less need for travel and more appropriate infrastructure such as sidewalks, cycleways and quality transit that enjoys priority in traffic are stressed.
• Healthy and safe for all are among the recent contributions of public health and medical sectors who are recognizing the importance of regular walking, bicycling, or walking to transit as key ingredients of a healthy lifestyle.

Aspects and antecedents of the new paradigm can be traced back several decades, but the growing interest in applying new paradigm approaches to the whole range of urban transportation challenges is relatively new and growing. Many progressive engineers are identifying with new paradigm approaches: will the rest of the profession follow and begin quickly thinking and practicing outside the box of the PMV ? Or will they continue to see transportation only through the windshield of the PMV?

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Bruun, E. and Schiller, P. (1996) “How cars devour urban space and time,” Urban Transport International, Paris: Groupe Actis, no 5, pp38–39

Bruun, E. and Vuchic, V. (1996) “Time–area concept: Development, meaning, and application,” Transportation Research Record 1499, Transportation Research Board, Washington, DC, pp95–104

Cairns, S., Atkins, S. and Goodwin, P. (2002) “Disappearing traffic? The story so far,” Proceedings of the Institution of Civil Engineers; Municipal Engineer 151. 2002 Issue 1 (March) pp 13-22

Dumbaugh, E. (2005) “Safe Streets, Livable Streets,” Journal of the American Planning Association, Vol. 71, No. 3, (Summer)

European Commission (undated) “Reclaiming city streets for people: Traffic Evaporation in urban areas,” (accessed 20Dec.2010)

Gilbreth, F. B. Jr. and Carey, E. G. (1948), Cheaper by the dozen. (accessed 1Dec.2010)

Hauer, E. (2000) “Safety in geometric design standards,” Proceedings 2nd International Symposium on Highway Geometric Design pp.11-35, Mainz 2000; earlier (1999) version available at

Levinson, D. (undated) “Comments on Long-Range Funding Solutions Symposium;”

Litman, T. (2010) “Generated Traffic and Induced Travel: Implications for Transport Planning,” (accessed 5Dec.2010)

Marohn, C. (undated) “Confessions of a Recovering Engineer”

Miller, S. (2009) “Traffic Engineering Myths Revealed,” , Aug 21

National Academies, The (2002), Key Transportation Indicators: Summary of a Workshop, National Academies Press, (accessed 10Dec.2010)

Newman P. W. G., Kenworthy J. R., Lyons T. J., (1988). "Does Free Flowing Traffic Save Energy and Lower Emissions in the Cities?" Search, Vol.19: pp. 267-272

Noland, R. B. (2001) “Relationships between highway capacity and induced vehicle travel,” Transportation Research Part A Vol.35, pp 47-72

Preusser, D. F., Leaf, Wm. A., DeBartolo, K. B., Blomberg, R. D. and Levy, M. M. (2002) “The effect of right-turn-on-red on pedestrian and bicyclist accidents,” Journal of Safety Research, Vol 13, No2 (Summer) pp 45-55

Pucher, J. and Buehler, R. (2010) “Walking and Cycling for Healthy Cities,” Built Environment, Vol. 36, No.4 (Dec.) pp 391-414, (accessed Dec. 20, 2010)

Richter, E. D., Barach, P ., Ben-Michael, E. and Berman, T. (2001) “Death and injury from motor vehicle crashes: a public health failure, not an achievement,” Injury Prevention 2001; Vol. 7, pp 176–178

SACTRA (1994) “Trunk roads and the generation of traffic,” Department of Transport, Standing Advisory Committee on Trunk Road Assessment, London

Schiller, P. L, Bruun, E. C., and Kenworthy, J. R. (2010) An Introduction to Sustainable Transportation:Policy, Planning and Implementation, Earthscan, London, U.K. ;see Chapters 7 & 8 for details of the new paradigm and its antecedents.

StreetsWiki (undated)

Wellar, B. (2010) “Measures to Mitigate Intersections That Are Conflict Zones for Pedestrians “ (Panel Presentation and Background Guide),

Wolf, K. L., and Bratton, N. (2006) “Urban Trees and Traffic Safety: Considering U.S. Roadside Policy and Crash Data,” Arboriculture & Urban Forestry, Vol. 32, No.4 (July) pp170-179

Zador, P. L. (1984) “Right-turn-on-red laws and motor vehicle crashes: A review of the literature,” Accident Analysis & Preventions, Vol. 16, No.3, (August) pp241-245

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About the author:

Preston L. Schiller  holds a doctorate in Sociology from Washington University (St. Louis). He has worked on Washington State and U.S. Clean Air and Transportation Acts with environmental coalitions and has served on numerous state and regional transportation planning and policy committees and task forces. He is currently Adjunct Lecturer, School of Urban and Regional Planning, Queen’s University, Kingston, Ontario. He is a consultant on transportation planning and policy issues for the North Sound Connecting Communities Project, a five county transportation forum for elected officials, planners, and interested citizens, and is completing a project on traveler public transportation information for the Whatcom Council of Governments.  You can contact him at

(This article was originally published in Canadian Civil Engineer (Winter/Hiver 2011/12 no. 28.5), special edition; “Thinking Outside the Transportation Box” and is reprinted here with their and the author's permission.)

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* You may find some interest in our recent article that tackles the basic behavioral issues here: Honk! Getting off the ox (when it comes to cars and cities).

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