> that's much more efficient in terms of space than a world where 80% of trips are via car and 20% are walked.
I feel like you are trying to say that it will require less space? Like roads can be made narrower or shorter? Why though? The road width is defined by the vehicle size and the number of lanes, and you don't want to cut the number of lanes below 1 but realistically you want 2 so a broken vehicle won't block traffic for everyone. And there are already not many 3 lanes in each direction roads so you are not saving much. Also most 3+ lanes roads I see are arterials and interstates, people driving those routes usually cannot walk them physically as they are tens if not hundreds of miles.
In the low traffic volume world of carriages, one lane in each direction is ample or even excessive for most roads. Many pre-car roads aren't wide enough to even accommodate one carriage in each direction at the same time.
The pre-car Europe and the US were not low traffic. E.g. the main street (Nevsky Avenue) in St. Petersburg, Russia is 200 feet wide since 1760s (and it was expanded from the original 65 feet because that was not enough for traffic).
If every destination needs parking for nearly its peak capacity then that creates substantial sprawl.
Similarly if an area gets a high volume of peak car traffic then over time it will tend to get more arterials and interstates connected to it.
As sprawl and road networks increase it becomes more difficult to get around without a car, incentivizing more cars, which requires more large parking lots / roads.
I don't know where you live but in every city in the US I had been there are minimum lot sizes and setbacks to prevent fires and flooding and those leave plenty of room for parking so I don't see how walking could change that (it's not like fire propagation and water absorption cares about your mode of transportation).
Not really, they existed before cars. As I said they are dictated by the fire safety, flooding danger and nuisance concerns. All the stuff you read on Reddit ("people want to live in tiny apartments but those are illegal to build", "it's illegal to have mixed commercial and residential use", "lot sizes are blown up by parking requirements") could be proven to be completely insane with few minutes of research.
I feel like you are trying to say that it will require less space? Like roads can be made narrower or shorter? Why though? The road width is defined by the vehicle size and the number of lanes, and you don't want to cut the number of lanes below 1 but realistically you want 2 so a broken vehicle won't block traffic for everyone. And there are already not many 3 lanes in each direction roads so you are not saving much. Also most 3+ lanes roads I see are arterials and interstates, people driving those routes usually cannot walk them physically as they are tens if not hundreds of miles.