As a thought experiment, imagine that you could design a city from the ground up and try to invent a transportation network that doesn't have pedestrians and cars next to each other.

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I imagine you could have five separate interconnected networks:

    1 Pedestrians
    2 bicycles
    3 personal cars
    4 trucks and buses
    5 light rail and inter-urban trains

Add in e.g. Christopher Alexander's Pattern Language (like "Country City Fingers), and I think you would really have something.