As a rule of thumb, you need 10k people / square km (25k people / square mile) to sustain local services and to enable most people live without using a car dail

As a rule of thumb, you need 10k people / square km (25k people / square mile) to sustain local services and to enable most people live without using a car daily. If 50% of land area is used for streets, parks, and commercial purposes, that 2-3k lot should house at least five people. I believe the average single-family home in an area with no housing shortage houses ~2 people. Once population density is substantially below that, there are not enough people to support public transit outside specific routes. Most people will need a car in their daily life. You can still find basic services such as supermarkets within a walking distance, but more specialized services such as restaurants and coffee shops become scarce outside central areas.