gian

I’d say 15 to 20 minutes.

Seems a little too much to me.

I would argue that higher education (and universities at the least) can be clustered.

And universities are already clustered (mostly), the problem for someone outside the big cities is the high school: there are many “types” of high schools and in small cities there is not enough students to have one of every type, so you need to move to another small town nearby. And even in big cities like Milan, there is not enough request to have every type of high school at a walkable distance from everyone.

In the end you would need a massive public transportation system (which is good to have anyway) but that must basically work on demand: as long as using a car to do few errands is going to take way less time because trains and buses have a timetable that make you wait 1 hour between them public transportation simply is not really usefull.

As a note tho: I am not saying that we can just plop this solution in place. It does require pretty intense city planning as well as time.

I don’t really think you can plan a city this way. Sure, you can try to have a city where you make a car mostly useless for some of the day by day activities but you would not be able to make the car really useless in a city.

For example having all the types of school of higher grade than the elementary and middle school.

But I suppose we should define “walkable distance” before.

Only up to a point. Small cities have not the critical mass of inhabitants to make certain services logical or even sustainable.

Having everything you need daily at a walkable distance only works in big cities, in small towns it do not work.

You just need to build a public transpotation system that can render cars useless for every use (shopping, commute, free time activities and so on) and that is usable from evertwhere to everywhere, even outside big (and small) cities.