Where has all the rubber gone?

Posted by srig8@reddit | AskUK | View on Reddit | 228 comments

Vehicle tyres are consumable because as you drive, the rubber disintegrates thus lessening the tread on the carcass until a certain legal depth is reached, and then that tyre is changed.

My question is thus:

Where does all the rubber go?

You don’t see pools of it on the roadside, so where is it?