The problem, we reaffirmed to each other, is that there are so seldom actually any workers around when we encounter orange barrels, lane closures, and threatening signs on the highway that we all get used to ignoring them, so that we're surprised to realize that there's actually someone working there when we fly by at 70 MPH. If they only told us to slow down when there was actually a reason to, it seems reasonable that enough people actually would that those who didn't could actually be a real enforcement target. Of course, they haven't tried that; every time someone gets worked up over a highway worker getting killed, they make the construction zones bigger, longer, and stupider, decreasing the chance that any given mile of marked zone has anyone working in it and increasing the pressure to ignore the signs.
My simple proposal, then: The contractors doing the work on the highways aren't allowed to own any warning signs, orange barrels, or such-like. They have to rent them from the state, by the day, on every one they actually use. Something like orange barrels are $1/day, and signs are $.25/ft2/day. In short, a direct and significant financial incentive to the construction companies to only disrupt traffic where they actually need to.
Anyone care to take a pot-shot at this?