EJScreen Indicators Overview – Traffic Proximity and Volume
What is the traffic proximity indicator?
The “traffic proximity indicator” measures the count of vehicles per day (average annual daily traffic- AADT) divided by distance. EJScreen presents traffic proximity using percentile rank, ranging from 0 (lowest) to 100 (highest) with higher scores representing closer proximities.
Why is traffic proximity important?
- Pollutants directly emitted from cars, trucks, and other motor vehicles are found in higher concentrations near major roads. Examples include particulate matter (PM), carbon monoxide (CO), oxides of nitrogen (NOx), and benzene, though hundreds of chemicals are emitted by motor vehicles.
- People who live, work, or attend school near major roads may have an increased risk for certain health problems including asthma onset and aggravation, acute respiratory infections in children, adverse birth outcomes (e.g., small for gestational age, pre-term, and low-birthweight infants), childhood leukemia, lung cancer in adults, and premature death.
- More than 72 million people live near major truck routes in the United States and are more likely to be people of color or low-income.
How does EJScreen create the traffic proximity indicator?
- Highway segments are from the Highway Performance Monitoring System (HPMS) lines and the annual average daily traffic counts are from the most recent HPMS release, Federal Highway Administration, U.S. Department of Transportation (DOT).
- Information about HPMS can be found on the FHWA website.
- For technical details on the calculations and source data, visit the EJScreen Technical Documentation.
Moving Forward – What You Can Do
- Stay informed on the latest relevant information and resources on the EPA Mobile Source Pollution site.
- Learn about the health effects related to mobile source pollution.
- See what the EPA and others are doing to reduce harmful health effects and exposure to mobile source pollution. Learn more about environmental justice work in transportation.