If the idea is to focus on tires, then why not just look at how many tires are manufactured each year? 100% of tires end up polluting something, somewhere. Or

If the idea is to focus on tires, then why not just look at how many tires are manufactured each year? 100% of tires end up polluting something, somewhere. Or, again if the focus is tire wear, there must be pretty good data about how much of a tire gets worn off before replacement, and how often they're replaced. It doesn't seem like it should be very complex to calculate how much tire is being emitted due to road wear.