UNECE to introduce methodology to measure particle emissions from tires
20 February 2024
Made from a mixture of natural and synthetic rubber and plastic polymers, including other chemical components, tires represent a significant source of non-exhaust emissions. Tire abrasion is produced when there is friction with the road surface, for example when vehicles turn, accelerate or brake.
Small particles break off from tires (this is expressed as tire weight loss) and are released into the air and onto the road surface and roadside environment. From there, they affect human health and can contaminate soil and waterways via road surface runoff, wastewater and airborne movement. They may eventually end up entering and polluting the ocean.
Following the adoption last year of a methodology to measure the emissions from braking systems, UNECE’s (United Nations Economic Commission for Europe) World Forum for Harmonization of Vehicle Regulations (WP.29) now turns to emissions from tires.
The Working Party on Noise and tires, with support from the Working Party on Pollution and Energy, adopted a proposal to introduce two methods to measure tire abrasion under UN Regulation Nº 117:
On open roads in vehicle convoys driving 8,000 km;
In laboratories on an abrasing rolling drum over 5,000 km.
Tire weight loss due to tire abrasion will be expressed in milligrams per kilometer per ton of load on the tire.
These measurement methods are expected to be applied in a market assessment exercise, aiming to collect abrasion data from diverse tire sizes, patterns and brands. Such data would then be used to determine tire abrasion limits to be incorporated in UN Regulation No. 117 by September 2025 for tires fitted to passenger cars (C1 tires).
Once these abrasion limits are in force, tire manufacturers will need to ensure that all the tires sold on the market are below the set limits. For those exceeding the limits, manufacturers will need to adjust their material composition or manufacturing process.
The proposal was prepared under the leadership of France and the European Commission and will become the reference methodology of the Euro 7 proposal of the European Union.
The measuring method is expected to be expanded to heavier vehicles with C2 and C3 type of tires during 2026 and 2027 to cover most road vehicle categories.
Once in force, these regulations will contribute to reducing microplastic pollution. In 2016, tire abrasion was estimated to represent 78% of the 1.3 million metric tons of microplastics entering the ocean.
The World Forum manages three Global Agreements on vehicles: 1958 Agreement (UN Regulations); 1998 Agreement (UN Global Technical Regulations); and 1997 Agreement (UN Rules on Periodic Technical Inspections). Any country that is member of the United Nations may participate in the activities of the World Forum and accede to the Agreements.
The Working Party on Pollution and Energy (GRPE) is one of the six subsidiary bodies of the World Forum. It concentrates its work on defining exhaust, energy efficiency and power measurement procedures for all modes of inland transport in order to limit environmental damage.
The Working Party on Noise and tires is another subsidiary body of the World Forum that prepares regulatory proposals on vehicle noise and tires for consideration and adoption by WP.29. To develop those requirements, GRBP conducts research and analysis.
Urgently needed.
That and the massive application of road salts are two of the uncosted hazards of driving everywhere.
Posted by: Davemart | 20 February 2024 at 01:25 AM
Very good, but a little too late because now with electric vehicles (BEVs), whether cars, vans and trucks weighing up to 40 tons, their tires are destroyed even faster and even more tire abrasion flows into the air that all living beings breathe!!!
A study was recently published in Florida in the USA where BEV tires are worn out and need to be replaced after just 5,000 miles. You should also consider that the raw materials for the tires come from endangered areas of the world - BEVs are still eco???
NO!!!!!!!!!!!!!!
Posted by: Herman | 20 February 2024 at 01:40 AM
Its a challenge for BEVs to get the weight down, one which led be the greatest genius the world has ever known has been simply ignored in favour of fat, heavy and inordinately fast.
Not that BEVs are alone in that, especially in the US there is an arms race to drive the biggest, heaviest car which is likely to do more damage than it sustains.
Posted by: Davemart | 20 February 2024 at 01:54 AM
There is have a new roadway under development, in the US, that is nearing deployment ready status. One advantage is the collection/treatment of water run off and elimination of the need for de-icing chemicals. This is only part of the solution but it is a start. There are other benefits such as power collection and buried distribution and telecom.
Alternative road surface project
But so far the tire has proven hard to replace with suitable performance/safety. Ideas such as Tweel from Micheline and some reconfigurable tire/wheels such as concepts out of Korea from Hankook and Bridgstone mostly still rely on rubber compound for tread. Though Bridgestone does have a site in US southwest growing alternatives to rubber for tires. A full replacement such as the ball rollers show in I Robot have so much regulatory hurdle I don't know if they will ever make it to market.
I mean, we could go back to wood and metal banding (wagon wheels) but then we would be changing entire paradigm.
Other direction is we go wheel less like the 2012 Total Recall film (or pick your sci-fi favorite flying car) and rubber wear is no longer issue.
As far as brakes material - we could do a two for solution such as mimic BEV with regeneration and only use friction brakes for last yard. Or we could use some other internal working medium to apply resistance to allow slowing down without ablative materials such as brake pads. Such an idea in principal like silicon dampers or radiator fan clutches. Since MB showcase a Siemens electric brake caliper (no fluid) we know alternatives exist.
As far as ICE brake alternatives using a motor/generator on shunt to stop would waste the heat into a sink VS recharge a battery. No real loss as friction brakes do essentially the same thing. How ever since we are starting over on braking then maybe replacing the alternator with this from the brakes may not be a bad idea. Same principal with fluid damping for brakes in that the fluid drives a motor/flywheel or builds pressure in a storage vessel and that energy is reused to aid acceleration.
All comes down to cost - can we make a system that reduces and/or eliminates the wear particles without adding a costly new system to vehicles?
Jason
Posted by: Variant003 | 20 February 2024 at 06:23 AM
Herman, do you have a link for this Florida study?
As far as I know, drivers experience similar tyre life for BEV vehicles, provided that they are using the right specification of tyre. Yes, BEV cars can be heavier, but so are trucks, and they have tyres that last for very long distances.
That being said, it's not uncommon for replacement tyres to last longer than original tyres. Part of that is because people can choose "taxi tyres" with less grip, worse braking, etc., but it's also probably a cost-saving measure.
Posted by: Bernard | 20 February 2024 at 08:30 AM
Bernard:
It really is pretty easy to google stuff up:
https://www.miamiherald.com/news/local/environment/climate-change/article284533695.html
' The tire manufacturer Michelin said conventional tires on electric vehicles consume tires 20 percent faster than on a gas-powered car — a figure commonly cited by EV makers as well — but Goodyear also has said they could wear up to 50 percent faster. Automakers and the tire industry are working on improvements.'
Posted by: Davemart | 20 February 2024 at 09:26 AM
It seems like EV tires should be narrower, higher pressure and a denser
rubber compound. Regenerative breaking should make the brake pads last longer but shouldn't have an effect on rubber dust in the environment.
Posted by: SJC | 21 February 2024 at 07:42 PM
Interestingly I get lousy wear out of my tires too, which is a much lighter car, a Peugeot 2008 GT.
The tires are specified as Goodyear all season.
They have an unusual system of traction control, where you can switch it to mud, gravel, or snow and ice mode and it alters the power output to enable better grip in those conditions, giving many of the benefits of 4 wheel drive in a 2 wheel drive car.
Video here:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=&cad=rja&uact=8&ved=2ahUKEwig1I6hxL6EAxV-gv0HHUVQAAcQtwJ6BAgOEAI&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DKwMGHeKxXEY&usg=AOvVaw0FAuo6y_STPEq28d1dyXjk&opi=89978449
What I am wondering is if enabling this, and perhaps the regenerative braking on electric cars, means that the tire compound has to be swapped to something softer, which wears less well than conventional tires?
Posted by: Davemart | 22 February 2024 at 12:33 AM