Low particle Emissions and lOw Noise Tyres

Project Information

LEON-T

Grant agreement ID: 955387

DOI

10.3030/955387

Project closed

EC signature date 22 April 2021

Start date 1 June 2021

End date 30 November 2024

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 4 112 446,25

EU contribution

€ 3 999 946,25

Coordinated by

IDIADA AUTOMOTIVE TECHNOLOGY SA
Spain

Periodic Reporting for period 2 - LEON-T (Low particle Emissions and lOw Noise Tyres)

Reporting period: 2022-12-01 to 2024-11-30

Summary of the context and overall objectives of the project

Currently, non-exhaust particulate emissions from vehicles are not regulated. Tyre noise is subject to labelling for passenger vehicles, but not yet for trucks.
Legislation is in preparation but will require a solid body of evidence of the mechanisms of generation, dispersion and potential health effects of both particulate and noise emissions, in order to introduce measures that are effective and widely accepted.

LEON-T has contributed to this body of evidence by investigating both particulate and noise emissions from tyres,
and in doing so define and propose practical standardised methods for both lab and road testing—of tyre abrasion rate
(mostly larger particles) and airborne particulate emissions and tyre generated noise.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The work carried out in LEONT in the period M1 – M42 is summarized below:

WP1: The management activity has progressed as expected and the milestones and submission of all the deliverables have been achieved satisfactorily.

WP2: Tire wear particle emissions have been investigated in the laboratory environment (VTI road simulator) and in the field (open roads and test tracks) using closed and open in-vehicle test arrangements. The correlation in the generation and physical characteristic of tyre particles and wear in these different environments is now understood.

WP3: Suitable methods for sampling, pre-treating and analysing TWP in environmental matrices have been investigated and developed.A new accelerated UV aging test for measuring degradation and fragmentation of TWP has been developed and an emission modelling has been built. The average chemical composition and physical properties of tyre particles, the effect of aging on them and its toxicology has been defined and reported.

WP4: The evaluation of tyre noise annoyance (including the measurement of physiological data) has been carried out together with sleep tests to understand and assess the impact of tyre noise on the cardiovascular system. The results show that tyre noise transients determine negative sleep effects and that additional psychoacoustic parameters, different from the traditional decibel, can be of value to better assess noise annoyance and sleep disturbance.

WP5: The technical specifications of an airless tyre concept has been defined as corresponding to the capacity of truck tyres of dimension 285/70R19. For this particular design used in LEON, the noise and rolling resistance performance of the corresponding prototype are similar to those found for conventional tyres. However, airless tyres for trucks could present significant advantages for circular economy.

WP6: Possible future new policies and mitigation strategies on tyre wear particle emissions, microplastics and noise emissions have been proposed and assess in terms of Cost/Benefit analysis.

WP7: The core of the communication activities has relied on the project website to display the different updates of the project (https://www.leont-project.eu/). Social media like Twitter and LinkedIn have been intensively used to attract external stakeholders, policy makers as well as general audience. A considerable number of technical and scientific publications have been carried out.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

LEON-T has made significant contributions to the validated body of evidence on how tyre-generated emissions impact public and environmental health. This allows the proposal of well-reasoned, justifiable mitigation measures— such as relevant and enforceable limits on those emissions. The project has also investigated the design and construction of an airless tyre, to explore the potential applicability of low-noise airless tyres for noise and rolling resistance reduction in trucks.

RESULTS and IMPACT AT THE END OF PROJECT (M1 - M42, 30/11/2024):

The technical and scientific community have now reached a better understanding of the following issues related to tyre generated emissions (particles and noise) and its impact on human health and the environment.

UNDERSTANDING TYRE ABRASION CHARACTERISTICS:

The assessment and characterisation of particle emissions have been achieved. The relationship between tyre tread wear and the corresponding particle emissions has been investigated and defined.
These results are of high importance to infer particle emissions factors from simpler measurements of tyre wear. D2.2 D2.3 and D2.4 have been published providing the details of the above findings.


UNDERSTANDING HEALTH RISK ASSOCIATED WITH AIRBORNE PARTICLES
Exposure to the various PM samples did not induce cytotoxicity and had no effect on metabolic activity of the cells. A slight increase in the production of few pro-inflammatory cytokines (IL-8 and MCP-1) was observed after exposure to PM samples from summer tyres, but other cytokines showed no clear response. Based on these experiments, it seems that coarse-sized PM generated by the VTI road simulator was not very toxic to human airway epithelial cells. In addition, the oxidative potential of total suspended particulates (TSP) was investigated using a novel, acellular immuno-assay based on lipid peroxidation. Un-aged TSP samples generally resulted in no, or a marginal increase in oxidative potential, in line with the limited toxicity observed in A549 cells. However, enhanced oxidative potential was observed for all TSP samples after UV aging for 8 hours (comparable to ~10 days of outdoor weathering).


UNDERSTANDING HEALTH RISKS ASSOCIATED WITH MICROPLASTICS
• Fate model applied to Tyre and Road Wear Particles based on SimpleBox4Plastics
• The emission model and fate model are made available under open source licenses for others to use and build upon.
• D3.4 was presented at SETAC EU 2024 meeting.
• Collaboration with LCA experts was set up to derive FF based on SimpleBox4plastics
• Several publications related to modelling and measurements are under preparation.


IMPACT ON EU / GLOBAL STANDARDS
LEON-T on on-road measurements of tyre particles demonstrated the difficulties for regulatory purposes and supported the Euro 7 approach of total mass loss. LEON-T investigations also demonstrated the sensitivity of the Euro 7 method on environmental and driving conditions and the need of a reference tyre.


IMPACT ON HDV TYRE NOISE
At the end of M42, the level of development of the airless tyre prototype was satisfactory to assess the feasibility of the concept.
Is has been found that the airless tyre concept used in LEONT does not offer clear noise and rolling resistance advantages with respect to conventional tyres.
The current design has allowed the definition of other fundamental design concepts that still need refinement to explore further potential of this type of airless truck tyre.

IMPACT ON CIRCULAR ECONOMY
Airless tyre designs such as the composite wheel demonstrated by LEON-T reduce the amount of rubber used in the tyre by 80%, as the load-bearing function of the carcass is taken over by a permanent construction that lasts the life of the vehicle. Airless tyre rubber also contains fewer contaminants as the tyre carcass contains plies of reinforcement fibres whereas the tread portion doesn’t. This means that end-of-life airless tyre treads are easier to recycle than complete tyres.
Even if the noise and rolling resistance performance of airless tyres is similar to the one of conventional tyres, still they offer advantages to boost the circular economy and reduce environmental impact

Graphical summary of LEON-T