Roads don’t have to be the biggest infrastructure cost in order for the argument to hold. You can say “this proposed development is financially unsustainable, i

Roads don’t have to be the biggest infrastructure cost in order for the argument to hold. You can say “this proposed development is financially unsustainable, it can’t even pay for its own roads, let alone all the other services it uses!” It’s helpful to have a simple heuristic like that to explain to non-experts why a project doesn’t make sense.