Spatio-Temporal Analysis of the Roadside Transportation-Related Air Quality (StarTraq 2024): Time-Series Analysis
Transportation-related air pollution remains a significant environmental and public health challenge in California’s San Joaquin Valley. This report presents a spatio-temporal analysis of roadside transportation-related air quality in Fresno County, California, from 1985 to 2023 with projections from 2024 through 2032. Using historical emissions inventories, projected vehicle miles traveled (VMT), infrastructure data, and land cover analysis, the study examines how transportation activity and urban expansion have influenced air quality across the region over time. Findings reveal that while PM10, PM2.5, NOx, SOₓ, CO, and CO₂ emissions from on-road mobile sources have declined significantly due to regulatory programs and cleaner technologies, the contribution of passenger vehicles has become proportionally more significant in recent years. Additionally, the study found that Fresno County experienced substantial land-use changes. These include the conversion of more than 130 km² of agricultural land into urban development and major losses in evergreen forest cover in the Sierra Nevada region, correlated with drought and wildfires, and tree mortality. At the same time, continued low-density residential growth has contributed to increased vehicle travel and ongoing air quality challenges. The findings highlight the interconnected relationship between transportation systems, land-use change, environmental conditions, and public health outcomes. This report calls for coordinated land-use planning, sustainable transportation investments, freight and emissions regulation, and environmental equity strategies to support healthier and more resilient communities throughout Fresno County and the broader San Joaquin Valley.
Jaymin Kwon
Dr. Jaymin Kwon is a Professor of Environmental and Occupational Health and Safety and the Chair of the Department of Public Health at California State University, Fresno. He obtained a B.S. and M.S. in Food Engineering and Biotechnology from Yonsei University, Korea, and an M.S. and Ph.D. in Environmental Sciences from Rutgers University, New Jersey. He joined Fresno State in 2011 after completing a postdoctoral fellowship at the University of Texas, School of Public Health in Houston. His research focuses on the epidemiological assessment of human exposure to traffic emissions and their adverse health effects, the development of sensors for air pollution monitoring, and the impact of traffic emissions on underrepresented microenvironments and communities.
Yushin Ahn
Dr. Yushin Ahn is an Associate Professor in the Department of Civil and Geomatics Engineering at California State University, Fresno. He received a B. Eng. degree in civil engineering and an M.Sc. degree in surveying and digital photogrammetry from Inha University, Korea, in 1998 and 2000, respectively. Additionally, he earned an M.Sc. and Ph.D. in geodetic science from The Ohio State University, Columbus, in 2005 and 2008, respectively. His research interests include digital photogrammetry, feature tracking, and sensor calibration and integration. Dr. Ahn received the Robert E. Altenhofen Memorial Scholarship from the American Society of Photogrammetry and Remote Sensing. He has been a certified Photogrammetrist since 2014.
Steve Chung
Dr. Steve Chung is a Professor in the Department of Mathematics at California State University, Fresno. He received a B.S. in Applied Mathematics from Cal Poly Pomona and his Ph.D. in Statistics from Florida State University. His research focuses on time series analysis and applied statistics.
-
Contact Us
San José State University One Washington Square, San Jose, CA 95192 Phone: 408-924-7560 Email: mineta-institute@sjsu.edu
