As if we don't have enough cliffs for our car-centric culture to drive off, there's this:
Q There are thousands of cars driving down the highway everyday; their tires get bald over time. I'm curious, where does all the rubber go?
A It becomes dust.
Of the more than 650,000 tons of tire tread that's worn off vehicles every year, much doesn't stay on the road. It goes into the air where wind, rain, and traffic movement keep it from staying on the road.
It is thought that about 50 percent of the total missing tire tread eventually does fall, depositing along roadsides. The rest can stay airborne, however, a problem for those allergic to latex (a component in tires) or with asthma.
Of course, that black dust is most likely to end up in the lungs of a cyclist.
I haven't found a calculation of the amount of rubber dust produced per mile by bikes versus cars, but it stands to reason a cyclist on two skinny tires produces a lot less than the same rider in a two-ton vehicle traveling at much higher average speed on four tires.
