Yet mixed use was largely abandoned and often outlawed in our stretch to suburbia. Zoning laws prohibited the co-location of commercial and residential uses. In more recent years, the machinery of city building has begun to realize that separating uses is inconvenient and terrible for urbanity. In many places, zoning laws have become more favourable to building homes near amenities and workplaces. Yet being near something is not enough to get people out of their cars. In the planning world, we generally use the five minute walk as the threshold in which people will choose not to drive. If you can walk there in five, it's more inconvenient to drive. But this is no guarantee. In fact, in big box power centres people will drive from store to store in the same parking lot. We are remarkably effective at building environments that are hostile to humans on foot.
However, there are many environments that are pleasant enough to persuade the average person to walk much further and longer than the five minute mark. That's largely a matter of urban design. When planned from the sky, cities can be parcelled up into zones of this, that, or a mix. We need that mixed use planning to ensure people live near their daily destinations, but let's not forget that we experience cities on the ground. If it does not feel right to be walking, most people will not walk unless they have no other choice. The same goes for cycling and transit.