Tire & Brake Dust Drift: 2D Roadside Pollution Simulator

Exhaust is only part of the pollution a road produces. Every tire and brake pad sheds fine particulate matter as it wears, and this 2D top-down simulator models where that dust actually goes: cars stream along a roadway shedding a physically-scaled mix of coarse (PM10) and fine (PM2.5) particles, a crosswind carries them across the roadside verge, and each particle falls at the real Stokes terminal velocity for its size class — so the heavier grains settle near the curb while the finer ones drift much farther, exactly as measured in real near-road air-quality studies. A side panel plots the same settling physics directly as height vs. time, and a strip chart tracks the population counts live. Toggle rain on and the dust already resting in the soil washes off into the storm drain by first-order kinetics, the same pathway that carries road grime into real streams after a storm.