Terrible roads seem far too local of a problem to be due to philanthropic billionaires diverting wealth. Quality seems to vary distinctly by county or city; I once lived near a city line where the line was demarcated by the abrupt transition from flawless asphalt to a minefield of potholes. Neither was a particularly famous, wealthy, or powerful county, and neither had resident billionaires.

No, I'm more suspicious of measures like California's Prop 13, as well as county and city level management.