Studies suggest smart growth policies, complete streets design, and transit-oriented development might help save lives
The US traffic fatality rate started slowly declining in the mid-1970s after the introduction of traffic-safety education programs targeting the highest-risk groups. These campaigns, and immense improvement in vehicle safety, drove traffic-related deaths downward for decades.
However, the 1990s saw an uptick in fatalities, and the decades following saw fatality rates closely track vehicles miles traveled (VMT)—the distance a population travels by personal vehicle in a given period. This suggests that our current methods for reducing traffic-related deaths have reached the limits of their effectiveness and that we need to develop a new paradigm.
West Side Highway in New York, New York
Traffic safety measures have historically reflected distance-based metrics, such as deaths per VMT. A new strategy for reducing crashes may be to reduce exposure—the amount traveled in a car to reach a destination. Transportation specialist Todd Litman advocates this methodology in his latest paper, A New Traffic Safety Paradigm. Litman, executive director of the respected Victoria Transport Policy Institute, writes that, “Although many demographic, economic, and geographic factors affect distance-based casualty rates, all else being equal, that is, for a given group or area, traffic casualties tend to increase when vehicle travel increases and decline when vehicle travel declines.”
_q_tweetable:Cities that focused on high-transit growth over the last decade experienced a 28% reduction in traffic fatalities compared to an 8% reduction in low-transit-growth cities._q_In many instances, comparing geographically similar states and regions reveals large crash-rate variations. These variations could reflect varying transport and land-use conditions and policies designed to reduce crash rates. For example, says Litman, 2012 data from the Center for Disease Control shows that, “Seattle, San Diego, and Portland have less than half the [traffic death] rates of Atlanta, Houston, and Sacramento,” which would support the hypothesis that policy reform can improve traffic safety.
Data from the Federal Highway Administration shows the highest per-capita traffic fatalities occur in areas with the highest per-capita annual vehicle mileage. Analyzing crash and traffic fatality rates from developed countries and the largest cities/regions in the US, Litman and others suggest that smart growth policies, complete streets design, and transit-oriented development (TOD) aren’t just equitable and sustainable tools for development but are also methods for improving traffic safety.
Cities that focused on high-transit growth over the last decade—such as Denver, Los Angeles, Portland, and Seattle—experienced a 28% reduction in traffic fatalities compared to an 8% reduction in low-transit-growth cities over the same period. On a related note, active-transportation modes such as walking and bicycling are more feasible (and appealing) in TODs. Litman states that, “Cities with active mode shares over 10% average about half the traffic fatality rates as those with active mode shares under 5%.” A pilot program led by the US Federal Highway Administration invested roughly $100 per capita in walking and biking improvements in four typical US cities. The program increased walking and biking by 23% and 48%, respectively, while walking and biking fatalities fell by 20% and 29%, respectively.
Six Forks Road in Raleigh, North Carolina
Currently, much evaluation of transportation planning measures level of service, which heavily considers vehicle speeds and delays. Transportation plans that account for these factors alone are inherently at odds with compact, mixed-use development, meaning that relying on this metric creates an incentive to develop environments that increase personal vehicle use and in turn, traffic fatalities. Transportation planning needs to take a more holistic approach and include a variety of modes, non-driver mobility, and economic development.
At Stantec, we’ve already adopted this approach. We’re leading the transformation of Six Forks Road in Raleigh, North Carolina, by planning for pedestrian, bicycle, and transit facilities across the 2.5-mile mixed-use corridor. Through innovative community engagement tactics such as charrette-based planning, keypad polling, and stakeholder interviews, we are gathering intelligence and supporting the community’s vision for sustainable and equitable development. Our team married elements of high-quality public space design and land-use forecasting with functional traffic modeling and facility design to create a sense of place.
Even well-established cities can make drastic changes to their urban transportation. We helped New York City completely transform its West Side Highway into a safe, efficient, and beautiful 5.4-mile complete streets urban boulevard. On any given day, hundreds of joggers, commuters, and families use the large, protected, and park-like multi-use paths. It has become an efficient and safe thoroughfare as well as a destination.
I find Litman’s argument convincing: by creating and supporting smart growth policies like the ones that shaped these projects, we can encourage active transportation, transit, and placemaking while reducing per capita VMT. This should help reduce traffic fatalities while simultaneously increasing equitable and sustainable development.
About the Author
Jonathan Garrett works to develop and launch innovative mobility solutions, such as self-driving vehicles and vehicle control software. He graduated from Arizona State University’s School of Sustainability, where he focused on technology, energy policy, and urban development.More Content by Jonathan Garrett