Construction Zones

Can someone please explain to me why every Department of Transportation (or, more correctly, their contractors) have to declare miles of road as an "active construction zone" when 1) it is not and 2) they are only working in less than a 100 feet of space?

On the drive back today, we encountered at least a dozen of these so-called "active construction zones," each more than several miles long, single lane, and slow speed. In each case, there was no work being done (and as near as I could tell there was no work scheduled for this or any other decade, let alone building season), and when there was evidence that work might, at one point in the far past or the near future be done, it was in a space that a man could walk comfortably to the port-a-potty, in other words several dozen yards. A mile, maximum would have sufficed to protect the workers (if there had been any) and not foobar the entire road for miles in each direction. Fortunately, there were only two zones where the traffic came to a screeching, snarled mess, and in both cases it was on the Canadian side of the journey and the work zone was active. It took us a half-an-hour to go a mile or so while everyone stopped to watch the workmen pour concrete...but rubbernecking is a different issue.