In late June, TCC attended a training on the health impacts of transportation.
Specifically, the training walked us through Integrated Transport & Health Impact Modeling (ITHIM), a method used to estimate aggregate changes to community health for different transportation scenarios (i.e. different combinations of transportation projects and policies in a given region). The training was led by Dr. Neil Maizlish, an epidemiologist who has worked extensively on ITHIM and the relationship between health and transportation.
While the ITHIM training got pretty technical, the takeaways were interesting and easy to understand: Transportation policies and projects can result in changes to infrastructure and traveler behavior that, in turn, impact the number of cars on the road, the number of opportunities to bike and walk, and traffic safety conditions for all modes.
All these changes can decrease or increase vehicle emissions, minutes of physical activity, and the number of crashes in the street, which ultimately have very real health impacts on the region’s residents:
- High concentrations of particulate matter in vehicle emissions can cause respiratory diseases and lung cancer.
- Low rates of physical activity are associated with health problems such as heart disease, stroke, diabetes, and depression.
- Traffic crashes, of course can cause injuries that result in death or lifelong disability.
In other words, this model is a great way to measure the health impacts of transportation reported by the Victoria Transport Policy Institute in February 2015.
Most standard travel demand models can forecast the amount of travel expected by different modes under a variety of scenarios. If you feed this information into ITHIM, along with region-specific disease rates, ITHIM can give you an estimate of the positive and negative health impacts for each scenario. Transportation agencies and public health departments across the U.S. are using ITHIM to evaluate and advocate for policies and projects that advance great health outcomes.
Given that King County, WSDOT, Sound Transit, and PSRC are moving forward with long-range planning efforts over the next few years, ITHIM is extremely relevant. It is encouraging that our public agencies are expanding their analysis to look at a variety potential impacts of the transportation system.
You can wonk out with some ITHIM research here.
