It's actually not--you're misunderstanding the broken window fallacy.
The classic example goes like this: "Let's break windows and hire people to replace them! That's a stimulus!" OP did not suggest digging holes into the street and filling them, however--fixing road wear-and-tear is an investment in public infrastructure.
Maybe I misunderstood, but I got the feeling from the OP I was responding to that he was suggesting we fill more potholes in order to stimulate the economy. I'm kind of working off the assumption that we are already filling the important potholes often enough, so filling more potholes just to spend money sounds like make-work.
The classic example goes like this: "Let's break windows and hire people to replace them! That's a stimulus!" OP did not suggest digging holes into the street and filling them, however--fixing road wear-and-tear is an investment in public infrastructure.