"Complexity catastrophes help explain why bureaucracy seems to grow with the tenacity of weeds. Many companies go through bureaucracy-clearing exercises only to find it has sprung back a few years later. No ever ever sits down to deliberately design a bureaucratic muddle. Instead, bureaucracy springs up as people just try to optimize their local patch of the network: finance is just trying to ensure that the numbers add up, legal wants to keep us out of jail, and marketing is trying to promote the brand. The problem isn't dumb people or evil intentions. Rather, network growth creates interdependencies, interdependencies create slow decision making and, ultimately, bureaucratic deadlock." (The Origin of Wealth by Eric D. Beinhocker)(Emphasis mine)

In this book on economic theory, there's a chapter about networks. While the previous quote talks about the effect of networks within companies, it is clear that the idea of local optimization within a network applies to other walks of life. A traffic jam isn't caused by "a bunch of morons who don't know how to drive", rather it is the cumulative result of each driver doing what's best for them: maintaining a safe distance from the car in front of them, and braking when that car brakes. With large volumes of traffic, jams are inevitable.

You'll see this theory in action in many other places too!