[throw3823423]

I think of the cities in Spain with the hottest climates, and I don't see a lot of crowds being protected by tree shade: Instead, the traditional design is narrower streets which aren't straight for very long, and even white cloth hanging across the street to provide the shade directly.

It's not that there's no trees, but you'll see them in parks and boulevards that might as well be narrow parks.

If anything, I see far more trees in the American midwest. Here the streets are very wide, with basically no foot traffic to speak of, and too much road for the number of cars that use the street in urban areas. You can definitely fit trees here, but that's because so much of that concrete is waste. The extra trees just mean more distances, and more distances means more parking lots and more concrete.