Center for Environmental Research & Technology

CE-CERT and Link Engineering Publish Landmark CRC Report on Non-Exhaust Vehicle Emissions

UC Riverside’s CE-CERT, in partnership with Link Engineering Company, has released a landmark report for the Coordinating Research Council (CRC) that provides the most comprehensive synthesis to date of non-exhaust vehicle emissions, the particulate matter generated not from tailpipes, but from brakes, tires, and road surfaces. As global transportation systems transition toward electrification and cleaner propulsion technologies, these non-exhaust sources represent an increasingly important share of on-road particulate pollution. The report, Systematic Review of Brake, Tire, and Road Wear Emissions for On-Road Light- and Heavy-Duty Vehicles (CRC E-143), evaluates more than 300 studies, offering the clearest picture yet of emission factors, measurement methods, regulatory developments, and emerging technologies across light- and heavy-duty fleets.

The project was jointly led by Link Engineering’s Carlos Agudelo and CE-CERT’s Dr. Zisimos Toumasatos, whose collaboration shaped the scope and execution of the systematic review. The effort was further supported and co-led by Professor Georgios Karavalakis and graduate researcher Zixuan Gong, who contributed to the literature assessment, regulatory analysis, and synthesis of findings. Together, the LINK and CE-CERT teams evaluated the available body of evidence and co-authored the final report.

As part of the review, researchers examined the strength, relevance, and consistency of published studies, prioritizing work that used reliable testing

methods and reflected current vehicle technologies. This comprehensive assessment revealed several challenges that the industry must address, including wide variation in testing practices, limited real-world data for newer vehicle platforms–especially electric vehicles–and a lack of standardized

reporting across studies. The report also points to growing research needs related to the environmental fate of particles and microplastics, as well as technologies and practices that could help reduce brake and tire wear emissions in the future.

For CE-CERT, the collaboration demonstrates the center’s growing leadership in an area that is rapidly becoming central to future air-quality policy. As electrified vehicles reduce tailpipe emissions but increase demands on braking and tire systems, non-exhaust emissions are poised to become a defining challenge of the next decade. The insights generated through CRC E-143 help establish the scientific foundation that regulators, manufacturers, and researchers will rely on as global standards continue to evolve.

Read the full report: https://crcao.org/wp-content/uploads/2025/11/CRC-E-143-4th-Final-Report-ZT-CA-FINAL.pdf