What Transportation And Public Health Can Learn From Each Other About Changing Public Behaviors

Which of the following is more likely to get you to drive slower down a street?  Or to get the majority of car drivers on that street to slow down?

·   A talk with a friend about the dangers of speeding to yourself and others.

·   A newly posted sign announcing a lower speed limit.

·   A stop sign placed in the middle of the block.

·   A series of speed bumps along the road.

Each of these might have an impact.  But changing the structure of the road is likely to have the greatest impact on the largest number of people over the longest period of time.  And the opposite is also true:  a long, smooth, straight-away down a wide road with few intersections or visual distraction invites speed – and most of us instinctively respond no matter what the posted limit.  Similarly, the lack of safe sidewalks or bike paths makes us much more likely to use our cars for even short trips.  Travel behavior is largely shaped by the transportation environment we inhabit.

So what?  Well, to the extent that transportation impacts global warming (it produces about a third of global greenhouse gases), or the livability of our neighborhoods (the transformation of urban villages into isolating suburban sprawl, and perhaps even the pulling apart of today’s multi-generational families, can be partially blamed on the automobile), or the growing diabetes epidemic (significantly caused by obesity which is significantly caused by lack of physical activity)…then how we move around matters.

In the public health world, the environmental equivalents to road structure are the systemic patterns that make some things easy to do – the “default choices” – and others more difficult.  Nearly two-thirds of US adults are overweight, and nearly half of that group is obese.  But our “obesogenic environment” surrounds us with opportunities to remain physically passive while we eat too much of faux-foods deliberately manufactured to trigger our evolution-based biological craving for fat, salt, and sugar.  “Everyone knows that you shouldn’t eat junk food and you should exercise,” says Kelly D. Brownell, the director of the Rudd Center for Food Policy and Obesity at Yale. “But the environment makes it so difficult that few people can do these things.”

And, as we all know, like New Year resolutions, dieting doesn’t work.  “If you take a changed person and put them [back into] the same environment, they are going to go back to the old behaviors,” says Dr. Dee W. Edington, the director of the Health Management Research Center at the University of Michigan.  “[But] if you change the culture and the environment first, when you get [personal] change it sticks.”

As another health researcher has pointed out, “Personal life-style is socially conditioned. . . . Individuals are unlikely to eat very differently from the rest of their families and social circle. . . . It makes little sense to expect individuals to behave differently than their peers; it is more appropriate to seek a general change in behavioral norms and in the circumstances which facilitate their adoption.”

Unfortunately, neither in transportation nor public health have the full implications of this reality been fully absorbed.  During the recent debates over national healthcare some of the fiercest attacks were against the “nanny state” proposal to encourage bicycling or the “anti-free market” idea of influencing the food system.  On the other hand, the fact that primary prevention and systemic health promotion were even part of the national debate was (minimally) encouraging.  And a new paper by the new Director of the Centers for Disease Control (CDC), Dr. Thomas R. Frieden, might provide the basis for renewed strategic thinking in both fields, although transportation advocates will have to start by translating some of its ideas and language into their own framework and jargon – a task that the following hopefully begins.  

Dr. Frieden’s paper describes a pyramid containing five levels of activity, with the bottom levels impacting an entire population and the top levels more focused on individual effort.  The bottom two levels are also the most cost-effective because they change the societal context for individual decision-making and switch the default choices to healthier from unhealthy ones – meaning that individuals would have to deliberately decide to put real effort into avoiding their benefit.  Examples start from the basic step of reducing poverty and changing the national food subsidy program to favor fresh fruits and vegetables.  And the list then expands to more traditional public health issues of providing clean water, dealing with sewerage, eliminating toxics and other pollutants, adding iodine to table salt and folic acid to bread, eliminating trans fats and reducing the amount of added salt in the food supply.  It includes reshaping economic incentives by increasing taxes on tobacco and alcohol and damaging foods such as sugar sweetened beverages.  On the built environment side these strategies include creating walkable and bikeable communities that facilitate social interaction, expanding affordable public transit, and designing buildings to promote stair use.

The middle level strategies include one-time or infrequent protective interventions that “generally have less impact…because they necessitate reaching people as individuals rather than collectively….[Examples include] immunization… colonoscopy…smoking cessation programs…[and] male circumcision [to reduce HIV transmission]…”

The top two strategy levels require ongoing, individually-focused interventions including medical care and counseling.  Although Dr. Frieden doesn’t mention it, these strategies might also include the modeling and promotion of positive alternatives by respected leaders along with public education programs that are intense and long-lasting enough to change mass culture – although these types of activity still require individual adoption and are hard to sustain if the surrounding environment and the socio-economic incentive system remains antagonistic to their message.   As Dr. Frieden points out, “successfully inducing individual behavioral change is the exception rather than the rule.”

How does this pyramid translate into a transportation policy that cost-effectively moves people and things while protecting our environment, strengthening community connections, facilitating public health, and promoting equitable economic growth?  How do we get people to change their transportation choices and behaviors?  We probably need strategies at every level of Frieden’s pyramid, but we need to remember which have the greatest leverage.

The bottom levels of the transportation strategy pyramid would focus on structural changes to the general environment.  The most fundamental strategy of this type would be to push for what could be called “transportation justice” – ensuring that the transportation system provides as many options and works as well for low-income communities as it does for the wealthy.   More traditional transportation issues would include reversing the past century of car-centric construction by prioritizing expanding facilities for walking, cycling, and public transit.  It would also require that the quality of travel for pedestrians, cyclists, and transit users be raised as high as possible, while the cost of using those modes is kept as low as possible.  We need, for example, bike routes that even the highly traffic intolerant majority of our population feels comfortable using, and new laws to protect the most vulnerable users of our roads from injury caused by those using more lethal machines.

We also need to change the economic incentives created over the past decades that pull people into cars:  the subsidies for road construction and maintenance, the low gas taxes and vehicle registration and parking fees.  We need to create new incentives that favor small, high mpg, non-polluting vehicles – or the decision to not have a car at all.  Because transportation and land-use are interactive, we need to redo our zoning and building codes to encourage mixed-use neighborhoods located within walking distance of transit hubs – this is not a “new intrusion” of the government into the marketplace, transportation and land-use patterns have always been shaped by government policies but in the past those policies were always on behalf of the oil and auto industries.

The middle-level strategies, only requiring one-time or infrequent connection with individuals, include bike-sharing and low-cost bicycle purchase programs to expand access to the equipment, changing the nature of school Physical Education programs to focus on “life-long activity” such as bike riding skills, setting up “Safe Routes To School” programs in every community, the inclusion of bike skill workshops for adults in workplace wellness programs, and the expansion of “Smart Choice” programs that help community residents learn more about how to get around without a car.

The top level, individually-focused strategies include setting up programs to support parents wanting to go for a walk or a bike ride with their children, getting health care providers to issue “walking and biking prescriptions” to their patients, having cultural and political celebrities visibly promote non-car alternatives, and a powerful media campaign that frames sedentary travel (like smoking) as both unhealthy and uncool.

Will all this be enough?  Probably not.  But Frieden’s pyramid provides a way to think about our options and helps us make sure that we are using the full spectrum of opportunities.

>> The Brownell and Edington quotes are from “Fixing a World That Fosters Fat” by Natasha Singer: August 21, 2010, NYTimes Business Day.  The Frieden paper is titled “A Framework for Public Health Action: The Health Impact Pyramid” and is found in the American Journal of Public Health, April 2010, Vol 100, No. 4.  The “Personal life-style…” quote is from G. Rose, K-T Khaw, and M. Marmot, “Rose’s Strategy of Preventive Medicine”, New York, NY: Oxford University Press; 2008. p135

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