Poor people live next to highways?

Or when we build the highway, we don’t raze the homes of the elite/wealthy/well-connected to do it, we do it in “bad neighbourhoods”

Or indirect effects: factories move/build next to the new highway (ease of moving materials+density of employees+ease of commuting because of the highway), contaminating the neighbourhood.

Source? As a counter anecdote: Madrid, where most people live near traffic, has the highest life expectancy in the EU at 85.4 years.