TRAX Air Quality Observation Project

  • Principal Investigator: Daniel Mendoza, Erik Crosman, Logan Mitchell, John Horel, John Lin (UU)
  • Funded for: $88,000
  • Study Period: 7/1/2018 – 6/30/2019
  • DAQ Contact: Whitney Oswald

Utah’s Wasatch Front experiences poor air quality episodes during both summer and winter due to its unique weather, topography, and pollutant emissions. During winter, inversions trap unhealthy concentrations of fine particulate matter (PM2.5), while high pressure during summer leads to elevated ozone (O3) levels. Spatially-explicit air quality data are needed to help inform the general public on the conditions they are experiencing and help characterize how air pollution affects the public’s health. Three years ago, air pollution sensors were deployed on two TRAX light rail cars that traverse the Salt Lake Valley on the Red and Green lines. The TRAX air quality monitoring effort is the first to utilize public transit for urban observations of trace species in North America.

TRAX is a unique platform available to capture spatial variations in ozone and PM2.5 when the light rail cars are operating. The three-year pilot program to test and evaluate the deployment of the sensors and real-time availability of the air quality monitoring has been a success and resulted in legislative support for this project to 1) support the dissemination of the information to air quality decision makers, the public, and researchers, 2) replace and repair aging sensors, 3) apply stringent quality control (QC) measures to the data set, and 4) maintain, calibrate and validate the measurements.

Photos and data from Logan Mitchell. Ozone and particulate matter sensors are housed on the Utah Transit Authority TRAX light rail.

Photos and data from Logan Mitchell. Ozone and particulate matter sensors are housed on the Utah Transit Authority TRAX light rail.

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Scope of Work (1.7 MB)

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