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.

This tool will help achieve the goal of the following objectives

Less Contamination
Less Emissions
Less Traffic Noise
Connectivity and Inclusion
Healthy Destinations
Less Traffic Violence
Active Transportation
Green Space

Estimation Technique

ITHIM relies on data from a variety of sources, including the U.S. Environmental Protection Agency’s National Emissions Inventory, the Federal Highway Administration’s Traffic Volume Trends database, and the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System. ITHIM uses these data sources to estimate exposure to transportation-related air pollution, noise, and traffic injuries at the county level.
ITHIM then calculates the health impacts of these exposures using a variety of methods, including the use of epidemiological studies and models that estimate the relationship between exposure and health outcomes. ITHIM estimates the number of cases of respiratory and cardiovascular disease, cancer, noise-induced hearing loss, and traffic injuries that can be attributed to transportation-related exposures.