University of California, Davis




ITHIM stands for Integrated Transport and Health Impact Model (ITHIM). The California version of ITHIM is a planning tool that answers the question of "How much benefit or harm to human health can we expect by changing the mix of active and motorized travel across a county, region, or the entire State of California?" ITHIM contrasts one travel pattern that serves as a reference with an alternative that has a different profile of fine particulate air pollution from vehicle exhaust, physical activity from walking and cycling, and injuries from traffic collisions. ITHIM calculates the change in deaths, years of life shortening and disability, and costs due to these changes in air pollution, physical activity, and traffic injuries. California ITHIM has been used by governmental agencies and advocates to assess the health impacts of updates to regional transportation plans under SB 375, Sustainable Communities Strategies; Goals of state and local health and transportation agencies; City and regional transportation projects and programs such as high speed rail and bike-sharing; and more. ITHIM is currently being used across the United States by state and local health departments, state and regional transportation planning agencies, and academic researchers.



Resource Type

Data and Tools


Extent: California


Last updated: Oct. 27, 2020