Integrated Planning for Community Health and Safety

Todd Litman's picture

Automobile travel imposes significant health risks. Traffic fatality rates, obesity and related illnesses such as diabetes, and total air pollution emissions tend to increase with per capita annual vehicle mileage. These risks help explain why United States residents have significantly shorter life spans than peer countries: average longevity is almost 1.5 years below the OECD average, despite spending about 2.5 times as much per capita on healthcare.

That sounds pretty negative so let's rephrase that statement: transport and land use policy reforms can provide substantial health benefits by creating communities where residents drive less and rely more on alternative modes. The public health community is starting to recognize this (APHA 2010; CDC 2010), but there is still plenty of confusion. Many experts fail to apply comprehensive analysis when evaluating healthy community planning strategies.

A key principle of good planning is that analysis should be comprehensive and integrated. You can call it sustainability or multi-objective, or integrated planning, but regardless of name it means that we consider all significant objectives, options and impacts when evaluating possible solutions to specific problems. This is in contrast to reductionist planning, in which agencies have narrowly defined goals and responsibilities, and so can rationally implementing solutions to the problems within their responsibility which exacerbate other problems facing society, and it undervalues strategies that provide modest but multiple benefits.

Let's apply this perspective to critique a recent report, Transportation and Health: Policy Interventions for Safer, Healthier People and Communities, by the Partnership for Prevention, which includes the U.S. Center for Disease Control and Prevention, the Safe Transportation Research and Education Center at the University of California at Berkeley, and the engineering firm Booz Allen Hamilton.

This report identifies transport policies that can improve public health by reducing vehicle emissions, increasing physical activity, and reducing traffic crashes. It attempts to be comprehensive (good). It evaluates a wide range of solutions (good), including TDM and smart growth policies (very good), but only considers them as emission reduction strategies; there is no recognition that reducing vehicle travel can also increase traffic safety (very bad).

This is a major omission. Transportation Demand Management (TDM, also called mobility management and VMT reduction strategies) and smart growth are among the most cost effective ways to increase public safety and health (Litman and Fitzroy 2010; Lucy 2003). For example, a few years ago, researchers Ewing, Schieber and Zegeer categorized 280 U.S. counties according to their sprawl index, which measures various land use factors such as density, mix and centricity. They found that the ten smartest growth counties have less than a quarter the average per capita traffic fatality rate as the ten most sprawled counties, as illustrated below in Figure 1. This is a huge benefit which many households care about, yet smart growth policies are primarily promoted as a way to reduce infrastructure costs or achieve environmental objectives, we fail to also promote it as a way to create safer communities.

Figure 1          Annual Traffic Death Rate (Ewing, Schieber and Zegeer 2003) 

Smart Growth traffic Safety ImpactsThe smartest growth counties have a quarter the per capita traffic fatality rate as the most sprawled counties. 


Similarly, transportation pricing reforms, such as more efficient pricing for roads, parking, vehicle insurance and fuel, can provide substantial crash reductions, in addition to other economic, social and environmental benefits, yet their safety benefits are generally overlooked. 

Figure 2          Vehicle Mileage and Traffic Fatality Rates (OECD Data)Mileage Versus Crashes 

This international comparision shows that per capita traffic fatality rates increase with annual vehicle travel.


Figure 2 shows a strong positive relationship between per capita vehicle travel and fatality rates among OECD (Organization for Economic Cooperation and Development) countries. Similarly, Figure 3 shows a positive correlation between vehicle travel and traffic fatalities for U.S. cities.

Figure 3          Vehicle Mileage and Traffic Fatality Rates For U.S. Cities (FHWA Data) 

Mileage Versus Traffic Fatality Rates 

This comparision of U.S. cities shows that per capita traffic fatality rates increase with annual vehicle travel.


As a result, transportation policy reforms that reduce vehicle travel can provide signficant safety benefits. For example, Grabowski and Morrisey (2004 and 2006) estimate that each 10% U.S. fuel price increase reduces total traffic deaths 2.3%, and each one-cent increase in state gasoline taxes will yield a 0.25% decrease in per capita traffic fatalities and a 0.26% decrease in fatalities per VMT. Leigh and Geraghty (2008) estimate that a sustained 20% gasoline price increase would reduce approximately 2,000 traffic crash deaths (about 5% of the total), plus about 600 air pollution deaths. Other transport pricing reforms, including efficient parking pricing (motorists pay directly for using parking spaces), Pay-As-You-Drive (PAYD) vehicle insurance (insurance premiums are based directly on annual vehicle mileage), and congestion pricing (tolls imposed on congested roads) probably provide similar or even greater safety benefits.

The Partnership for Prevention report emphasizes the conventional narrative that traditional traffic safety programs are successful, because it measures risk per mile rather than per capita. It states that during the last four decades, "the number of fatalities and injuries per mile driven dropped by nearly 80 percent, a truly dramatic achievement," without mentioning that the U.S. has the highest per capita traffic fatality rate among peer countries. As a result of this myopia the report only recommends traffic safety strategies that reduce per-mile crash rates, it ignores traffic safety strategies that reduce per capita mileage such as TDM and smart growth.

This is important because TDM and smart growth face significant obstacles. For example, PAYD vehicle insurance is an effective demand management strategy, and because it gives higher risk motorists a greater financial incentive to reduce their mileage, it can provide extra traffic safety benefits, yet currently only one North American insurance company, MileMeter, offers fully-marginal PAYD. Similarly, smart growth policies must overcome resistance by entrenched interests, such as the National Association of Home Builders, as discussed in my recent column, An Inaccurate Attack On Smart Growth.

More comprehensive analysis helps identify integrated solutions that are truly best overall, considering all benefits and costs. It can also identify opportunities for cooperation among diverse interests. For example, if we recognize that transportation pricing reforms can reduce traffic congestion, infrastructure costs, accidents, obesity, pollution emissions and sprawl, we can build a coalition among transportation agencies, business groups, public health officials and environmentalists. Similarly, recognizing the full health and safety benefits of more compact development can increase political support for smart growth policies.

I believe that the root of many contemporary problems is a failure to apply comprehensive, integrated planning analysis. I would expect public health professionals to be among the first to appreciate its value, so I am surprised that the Partnership for Prevention failed to apply it in this major, recent study.


References and Information Resources 

APHA (2010), The Hidden Health Costs of Transportation: Backgrounder, American Public Health Association (; at

J. Ball, M. Ward, L. Thornley and R. Quigley (2009), Applying Health Impact Assessment To Land Transport Planning, Research Report 375, New Zealand Transport Agency (; at

Judith Bell and Larry Cohen (2009), The Transportation Prescription: Bold New Ideas for Healthy, Equitable Transportation Reform in America, PolicyLink and the Prevention Institute Convergence Partnership (

CDC (2010), CDC Transportation Recommendations, Center for Disease Control and Prevention ( 

Reid Ewing, et al. (2003), "Relationship Between Urban Sprawl and Physical Activity, Obesity, and Morbidity," American Journal of Health Promotion, Vol. 18, No. 1 (, Sept/Oct. 2003, pp. 47-57, at

Billie Giles-Corti, Sarah Foster, Trevor Shilton and Ryan Falconer (2010), "The Co-benefits for Health of Investing in Active Transportation," NSW Public Health Bulletin, Vol. 21, No5–6, pp. 122-127; at

David C. Grabowski and Michael A. Morrisey (2004), "Gasoline Prices and Motor Vehicle Fatalities," Journal of Policy Analysis and Management (, Vol. 23, No. 3, pp. 575–593.

David C. Grabowski and Michael A. Morrisey (2006), Do Higher Gasoline Taxes Save Lives?" Economics Letters (, Vol. 90, pp. 51–55.

Sonja Kahlmeier, Francesca Racioppi, Nick Cavill, Harry Rutter, and Pekka Oja (2010), "‘Health in All Policies' in Practice: Guidance and Tools to Quantifying the Health Effects of Cycling and Walking," Journal of Physical Activity and Health, Vol. 7, Supplement 1, pp. S120-S125; at

J. Paul Leigh and Estella M. Geraghty (2008), "High Gasoline Prices and Mortality From Motor Vehicle Crashes and Air Pollution," Journal of Occupational and Environmental Medicine, Vol. 50, Is. 3, March, pp. 249-54; at

Todd Litman (2004), If Health Matters: Integrating Public Health Objectives into Transportation Decision-Making, Victoria Transport Policy Institute (; at; previously published as, "Integrating Public Health Objectives in Transportation Decision-Making," American Journal of Health Promotion, Vol. 18, No. 1 (, Sept./Oct. 2003, pp. 103-108; at

Todd Litman (2011), Pricing For Traffic Safety: How Efficient Transport Pricing Can Reduce Roadway Crash Risk, Victoria Transport Policy Institute (; at

Todd Litman and Steven Fitzroy (2010), Safe Travels: Evaluating Mobility Management Traffic Safety Benefits, Victoria Transport Policy Institute (; at

William H. Lucy (2003), "Mortality Risk Associated With Leaving Home:  Recognizing the Relevance of the Built Environment," American Journal of Public Health, Vol 93, No. 9, September, pp. 1564-1569; at

NCBW (2010), Increasing Physical Activity Through Community Design: A Guide for Public Health Practitioners, National Center for Bicycling and Walking (; at

PfP (2011), Transportation and Health: Policy Interventions for Safer, Healthier People and Communities, Partnership for Prevention (Safe Transportation Research and Education Center, Booz Allen Hamilton, and the Centers for Disease Control and Prevention) (; at
Todd Litman is the executive director of the Victoria Transport Policy Institute.



Michael Lewyn's picture


Has anyone modeled how much of that 1.5 year gap would be erased by smarter transportation policies? (I instinctively think very little, but I could well be very wrong!)

Todd Litman's picture

Magnitude of Transportation Health Risks

That's a good question, Michael.

I suspect that transportation health risks DO explain a major portion of the discrepancy. As discussed in my report, "If Health Matters" ( ), traffic accidents, air pollution and sedentary living are major contributors toward the three largest causes of "potential years of life lost" (PYLL) in the U.S.: cancer, cardiovacular disease and motor vehicle crashes. According to data illustrated in Figure 2 of that report, traffic accidents caused about 1.2 million years of lost life in 1998 when the U.S. had 270 million residents, about a 4% reduction or nearly 0.35 years per capita based on a 78-year average lifespan. Assuming that vehicle air pollution causes a similar number of PYLLs, and sedentary living causes more, you can conclude that the high rate of automobile dependency in most U.S. communities is a major contributor to the nation's poor health performance compared with peer countries.

I admit that this is a pretty crude analysis and I encourage anybody with the skills and time to develop a better model. This is not to deny other factors that contribute to poor health outcomes, such as inadequate healthcare for lower-income residents and associated high rates of infant mortality. However, I believe the available evidence indicates that transport and land use policies which create communities where residents drive less and rely more on alternative modes can significantly improve residents' health, longevity and welfare. This is good news, because these same reforms help achieve over economic, social and environmental objectives; and I can report from personal experience are enjoyable: come for a walk or bike ride here in Victoria, Canada to see for yourself, as described in my new report, "Planners’ Guide To Victoria: Highlights For Urban Exploration And Discovery" ( ).

One additional note. Many people assume that improved emission control technologies have virtually eliminated motor vehicle air pollution health damages. This is untrue. Although some emissions have been significantly reduced, others, particularly fine particulates, have not. The latest research indicates that fine particulates are still a major contributor to cardiovascular disease and cancers (see ).

Todd Alexander Litman
Victoria Transport Policy Institute
"Efficiency - Equity - Clarity"

Too complex to tease out meaningful findings, I reckon

Yes, and these particulates are a much worse problem in high density areas with traffic congestion, than in low density areas with faster moving traffic.

Increased density NEVER causes sufficient "mode shift" to negate the effects of congestion resulting from the population increase.

There is a growing amount of research on the NEGATIVE health effects of high density.

It is simply impossible to tease out all these complexities.

Total fatalities and fatalities/VMT have been steadily going down for decades. It is now safer to drive in the U.S. than it has ever been.

Is obesity something that justifies an assault on people's freedoms? It would be much cheaper to just have a few Kommisars chase these people round the block a few times with a bullwhip every day, than to impose costly prescriptions of urban form.

One obvious thing is that there is a huge health and life expectancy advantage to the societies in the world with "post development" "automobility", than those that do not have this - and over our own ancestors who did not. It is simply impossible to have MUCH "social mobility" and equally shared wealth creation, without the "democratization" of land ownership and the minimization of "monopoly rent" that is enabled by "sprawl" and "automobility". In fact, the volatility of "property cycles" in economies without sprawl and automobility are a massive encumbrance on their long term economic performance. No nation is going to become as "well off" as Americans and Europeans, without "sprawl" of at LEAST "European" levels. (This being only a few percentage points different to US levels, with the exception of the economic basket-case, Britain).

Health effects, another study - and more

Schweitzer and Zhou (2010) "Neighborhood Air Quality, Respiratory Health, and Vulnerable Populations in Compact and Sprawled Regions"

"......Compact development and infill do not solve air quality problems in all regions or for all residents of a given region. Planners should take differences in neighborhood air quality and human exposure into account when planning for new compact developments rather than just focusing on emissions reductions......."

THIS one also covers health impacts among other things:

Howley (2010) "‘Sustainability versus Liveability’: An Exploration of Central City Housing Satisfaction"

Howley and colleagues are doing some interesting research. HERE, they suggest that modern high density living populations are highly transient:

Howley, Scott and Redmond (2008) "An Examination of Residential Preferences for Less Sustainable Housing"

Health Effects of Automobility

"there is a huge health and life expectancy advantage to the societies in the world with "post development" "automobility", than those that do not have this - and over our own ancestors who did not.

So, how does health and life expectancy of the more auto-dependent United States compare with the health and life expectancy of less auto-dependent Japan, Netherlands, and Denmark? Those of us who call for less auto dependency are obviously not calling for a return to the conditions of our ancestors who burned coal for heat - much less to the conditions of our ancestors who lived by hunting and gathering.

Note that this comment about the benefits of automobility belies Wodehouse's claims elsewhere that "the only thing I oppose about "Smart Growth" is urban growth boundaries or proxies for them."

In one of today's comments, he says that he supports "....allowing higher development densities, more housing types, reduced parking requirements....."

In another of today's comments, he says that "particulates are a much worse problem in high density areas with traffic congestion, than in low density areas with faster moving traffic. ... There is a growing amount of research on the NEGATIVE health effects of high density."

That is another reason to avoid blizzards of comments: they make your self-contradictions too obvious. Those of us who read his comments know that he is rhetorically in favor of high densities but really in favor of low suburban densities.

Charles Siegel

Prepare for the AICP Exam

Join the thousands of students who have utilized the Planetizen AICP* Exam Preparation Class to prepare for the American Planning Association's AICP* exam.
Starting at $199
Planetizen Courses image ad

Planetizen Courses

Advance your career with subscription-based online courses tailored to the urban planning professional.
Starting at $14.95 a month
Wood necklace with city map

City Necklaces

These sweet pendants are engraved on a cedar charm with a mini map of selected cities. The perfect gift for friends and family or yourself!

Stay thirsty, urbanists

These sturdy water bottles are eco-friendly and perfect for urbanists on the go.