The separarion of streets for people and roads for cars means better, faster car flow too. The problem America has is that it tries to smoosh cars and peds on the same roads, making them terrible for both. Instead of being able to do 40 on every road, think instead of doing 15 on some roads and 60 on others.

The amount of actual ped zones in America is pretty small anyway, think downtown shopping precints and stuff like that, so the majority of roads would still be car dominant.

Tell me you’ve only ever lived in North America without telling me you’ve only ever lived in North America.

North American goods actually make most of their way through water and rail but the "final mile" costs are much higher and therefore still significant. In places like Africa this effect is probably more magnified as rail system is far more limited and you must drive from the port.