Somebody else mentioned Strong Towns, and that's a good organization who have been thinking about this issue for a while.
You're right that they're not easy problems, and it's because it encompasses more than just road layouts, but city design, land use and culture. North American cities, for example, tend to put a bunch of their amenities like supermarkets in a few places, with homogeneous swaths of housing-only suburbs so people have to drive, and those drivers have to use all the same roads to get where they're going.
One thing you've noticed is the so-called "stroad", a highway that's attempting to be both a road (an efficient, high speed connection) and a street (a destination, where people live, work and shop). These two objectives get in the way of each other, so you end up with a road that can't carry traffic well because it has too many entrances and intersections, and a street that is hostile to anybody not in a car. Generally, efficient road design separates these two, so the higher speed connections don't serve any destinations directly.
You're right that they're not easy problems, and it's because it encompasses more than just road layouts, but city design, land use and culture. North American cities, for example, tend to put a bunch of their amenities like supermarkets in a few places, with homogeneous swaths of housing-only suburbs so people have to drive, and those drivers have to use all the same roads to get where they're going.
One thing you've noticed is the so-called "stroad", a highway that's attempting to be both a road (an efficient, high speed connection) and a street (a destination, where people live, work and shop). These two objectives get in the way of each other, so you end up with a road that can't carry traffic well because it has too many entrances and intersections, and a street that is hostile to anybody not in a car. Generally, efficient road design separates these two, so the higher speed connections don't serve any destinations directly.