Houston Texas is like that. A few other cities too. There are no zoning laws. It has pros (economic), it has cons (personal) but it does work in specific situations. It allows the free market to decide where it wants to go. Zoning sometimes fails because you end up with massive neighbors without a grocery store or business areas too close together without residential areas nearby and forcing people from other areas to commute there. It can get messy. But when there are no zoning laws businesses naturally gravitate toward heavy loud noisy streets and intersections anyway. Industrial companies naturally go far out where the land is cheaper. And residents go towards the areas that suit their lifestyle or that they can afford. It doesn't always work out perfectly but that's the theory anyway. Anyone from Houston please chime in.
