Suggested Citation:
Karner, Alex, Dana Rowangould, Yizheng Wu, Ofurhe Igbinedion, Jonathan London (2017) NCST Research Report: Development and Application of an Integrated Health Impacts Assessment Tool for the Sacramento Region. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-17-37

Plans crafted by metropolitan planning organizations (MPOs) lay out how billions of dollars in transportation investments will be made over a 20 to 30-year time horizon. Federal transportation authorizations require MPOs to identify and track key indicators of system performance (e.g. collision rates, emissions, congestion) to ensure that they are stewarding public funds wisely to meet specific goals related to safety, environmental performance, and congestion mitigation, among other areas. Concerns related to preventing discriminatory impacts of planning activities, motivated by Title VI of the 1964 Civil Rights Act, also compel agencies to assess the impacts of plans on different demographic groups.

At the same time, there is a growing desire among transportation planning agencies to develop transportation and land use plans that shift travel behavior away from driving and towards more active travel modes. Research has shown that living in areas where walking and bicycling are convenient leads to greater use of those modes, which can lead to improved health outcomes due to increases in physical activity. But increasing non-motorized travel can also increase active travelers’ risk of traffic injury and exposure to air pollution. Analytical tools that assess the tradeoffs between transportation plan alternatives are needed to inform public debate and ensure that gains in some health outcomes are not being undermined by losses elsewhere. Additionally, questions remain about who will benefit from plans that promote increases in active travel.

The aim of this project is to investigate the distribution of public health impacts resulting from a regional transportation plan in the six-county Sacramento Area Council of Governments (SACOG) region. This report summarizes findings related to our three key goals:

1. Comparison of different approaches to assessing the public health impacts of transportation plans. Multiple datasets, tools, and methods exist for conducting such assessments. We synthesize known information about them and highlight their similarities and differences. We focus on comparing ITHIM and the California Public Health Assessment Model (C-PHAM) which is integrated into UrbanFootprint. Both have been applied in several areas of California.
2. Employ a refined version of the Integrated Transportation Health Impacts Model (ITHIM) to quantify health impacts resulting from the 2016 SACOG Metropolitan Transportation Plan/Sustainable Communities Strategy. We adapt ITHIM to produce estimated changes in death and disease burden by race, ethnicity, and income categories. Results are presented as totals (to indicate the magnitude of impacts) as well as standardized by age and population (to facilitate comparisons of risks faced by different geographic areas and populations.) We also present results for each of SACOG’s component counties.
3. Report on the development of a user-friendly web interface for summarizing ITHIM results. In response to the requests of various health and sustainability stakeholders in the SACOG Region, we created a web version of our tool that can be used to visualize existing model results. This web interface allows a user to tailor the results shown by geographic area, scenario, demographic group, outcome, and units. Future iterations of the tool will be able to simulate user-defined scenarios.

Our results demonstrate the utility of analyzing and representing the public health impacts of transportation plans in a user-friendly way for planners, policy makers, and advocates. The methodology used in this project can serve as a model for those working on active transportation, public health, and regional equity in other locations across the U.S.