DLR Tire and Road Wear Particle Emission Testing Methodology–Collection System Influence and Repeatability Assessments

<div class="section abstract"><div class="htmlview paragraph">Tire and road wear particles (TRWP) have emerged as air quality hazardous matters and significant sources of airborne microplastic pollution, contributing to environmental and human health concerns. Regulatory initiatives, such as the Euro 7 standards, emphasize the urgent need for standardized methodologies to quantify TRWP emissions accurately. Despite advancements in measuring tire abrasion rates, critical gaps persist in the characterization of airborne TRWP, particularly regarding the influence of collection system design and influencing parameters on measurement accuracy and repeatability. This study addresses these challenges by designing a controlled methodological framework that aims to minimize the influencing effects and ensure comparability in TRWP emission quantification results.</div><div class="htmlview paragraph">At the German Aerospace Center (DLR) dynamometer testbench in Stuttgart, Germany, a methodical framework was established to ensure the repeatability and comparability of TRWP measurements, incorporating standardized tire testing conditions and particulate matter sampling methodologies. The results indicated that the DLR® housing-based system with an encapsulated tire exhibited higher particle concentrations in fine and ultrafine fractions compared to the nozzle-based system. Statistical analyses following ISO standards confirmed that the DLR® housing system demonstrated higher measurement consistency, with lower deviations in repeated tests. In contrast, the nozzle system showed higher deviations, particularly in the PM10 fraction (i.e., particles with aerodynamic diameter less than 10 μm), suggesting potential particle losses and lower collection efficiency.</div><div class="htmlview paragraph">These findings emphasize the importance of designing measurement methodologies that minimize the influence of external factors and improve the repeatability of TRWP characterization. By establishing a standardized and comparable framework that isolates tire-road interaction effects from environmental and surface variability, this study enhances the accuracy of TRWP emission measurements. The proposed methodology aims to serve as a robust foundation for regulatory frameworks, offering valuable insights into the optimization of current TRWP measurement techniques.</div></div>