As production becomes increasingly clean and knowledge-based, as our urban economies tip dramatically to service industries, as racism and ethnic animosities ebb, and as the model of mixed use becomes more and more persuasive and visible, cities are in a position to dramatically rethink zoning as a medium for leveraging and usefully complicating difference, rather than simply isolating it.
Raskin, in his essay on variety, suggested that the greatest flaw in city zoning is that it permits monotony. I think this is correct. Perhaps the next greatest flaw is that it ignores scale of use, where this is an important consideration, or confuses it with kind of use.
Work uses suggest another bugaboo: reeking smokestacks and flying ash. Of course reeking smokestacks and flying ash are harmful, but it does not follow that intensive city manufacturing (most of which produces no such nasty by-products) or other work uses must be segregated from dwellings. Indeed, the notion that reek or fumes are to be combated by zoning and land-sorting classifications at all is ridiculous. The air doesn’t know about zoning boundaries. Regulations specifically aimed at the smoke or the reek itself are to the point.
Now, I understand deadlines. I understand that the plane will take off whether or not I’m on it, or the importance of beating the holiday retail rush, or that "the show must go on". It is perfectly clear to me how people use timekeeping technology to coordinate social activity. It’s actually quite remarkable when you step back and look at it. But, over the years, I have observed that there is a difference between those examples and the ones around the delivery of Things, which tend to be completely arbitrary. When you wrap an arbitrarily complex endeavor up in a neat launch date, the goal seems to be more about coercing the people beneath you to absorb the overhead of all the details you left out—that or sweating it yourself. As a tool for coordinating human activity, I have come to believe that the Thing-deadline calculus is, considering more sophisticated alternatives, unnecessarily crude.