Ricardo, in collaboration with the Arup AECOM consortium, is supporting the UK Department for Transport (DfT) in developing a system for measuring non-exhaust emissions (NEE) of particles, under real-world driving conditions.

Non-exhaust emissions of particles from road vehicles primarily arise from a combination of brake wear, tire wear, road surface wear, and the resuspension of dust particles. Emission data from the UK NAEI (National Atmospheric Emissions Inventory) estimate that NEE are now the primary source of coarse and fine particulate matter (PM₁₀ and PM_2.5) from road transport in the UK.

A key aim of this project is to improve knowledge on NEE and address the gaps so it can be used to inform policy and legislation aimed at reducing tire and brake wear particulate emissions. As the shift towards electric and hybrid vehicles increases it is important to address these gaps now.

A December 2020 report from the OECD on NEE from road transport noted that:

While they stand to eliminate exhaust emissions, this report shows that electric vehicles are not likely to provide substantial benefits in terms of non-exhaust emissions reductions. Regenerative braking systems can reduce brake wear, but tyre wear, road wear, and road dust resuspension remain significant sources of non-exhaust emissions from electric vehicles. Non-exhaust emissions from these sources can in fact be higher for electric vehicles than for their conventional counterparts, as the heavy batteries in electric vehicles imply that they typically weigh more than similar conventional vehicles. This is particularly the case for electric vehicles with greater autonomy (driving range) that require larger battery packs.

—“Non-exhaust Particulate Emissions from Road Transport : An Ignored Environmental Policy Challenge”

Ricardo will contribute expertise in air quality, particle measurements and automotive emissions to design and test a system to determine the overall feasibility of an on-board tire and brake wear measurement.

Establishing an accurate and efficient system that can successfully detect NEE of particles under real-world driving conditions will help to better inform our current knowledge of how different brake, tire and road materials perform under real-world driving conditions and how this contributes overall to transport related pollutant emissions.

—Paul Willis, Technical Director for Air Quality Measurements at Ricardo

Ricardo Energy & Environment’s Particle Measurement Center (PMC) and Automotive teams have previously co-operated extensively on the Particle Measurement Program (PMP). The PMC continues to support PMP-related applications by providing an ISO17025-accredited calibration service for solid particle counting instrumentation (both particle counters and sample conditioning systems) used for regulatory compliance measurements of vehicle emissions by the automotive sector around the world.