Comedy in the unlikeliest of places

Working my way slowly but steadily through the near-1000 pages of joy that is the proofs of this book, I came across the Manning Equation. It's "the most commonly used equation to analyse open channel flows", apparently.

What price, then, discovering that for calculating roadway flows you need a derivative of the Manning Equation called the Izzard Equation?

What's next? The Coogan Theorem? The Iannucci Proof?