First, I live 150 yards from a major freeway - I-90 in WA, it's three lanes in each direction here. There are no tiny black particles over everything in surroundings, and my outdoors AQI (from my own sensor) is normally in single digits and basically only ever gets above 50 if it's wildfire smoke or the neighbors are burning something.
But second, if we developed a reliable and cheap way to, say, teleport people over long distances, why not tear it down?