It's probably cultural, but yes, the idea in a suburban area like that is that the drivers are there to drive to/from the houses there, not cut through, and the

It's probably cultural, but yes, the idea in a suburban area like that is that the drivers are there to drive to/from the houses there, not cut through, and they drive slowly in the development because there's children playing, animals, etc. When commuters cut through, they drive too fast (it's not like there's cops there all the time looking for speeders) and that's dangerous when there's children around. The roads are made small because it's only supposed to be for residential traffic for the houses there; other people are supposed to use the high-capacity streets that are designed for that purpose. Does France not have differently-sized streets for different traffic needs? You don't have highways there?