Warnings that don't work

On my way home from the property tax office, I saw a road sign that made me think long and hard about what we writers do. It's a diamond-shaped sign, gold with a black border - the standard US format for free-form advisories. It says:
CAUTION: HILL BLOCKS VIEW

Why yes, so it does. Hills do that as you approach them; otherwise they'd be valleys or plains. I wondered, How much did we taxpayers fork over to have the highway department inform us of the obvious? But wait, there's more. The hill in question is neither the first nor the last on this road. It is, after all, a road through the Texas Hill Country.

Perhaps there is something special about this hill, then.

At this point my philosophical quest began to make headway.

What's special about this particular hill is not that it is, like most hills, opaque. The significant data are that it has two crests, and between them is a large church that's often used by civic organizations as a meeting-place. People driving out of the church's driveway are at significant risk of being hit at highway speed by their neighbors, or by the gravel trucks coming from the quarry just down the road. This information would not fit on a road sign, however; so we ended up with an advisory that states the root problem without giving us a clue about its all-too-common consequences.

Drivers cannot change the opaqueness of hills; but if we are aware that we are on a blind approach to a heavily trafficked driveway, we can exercise caution by slowing down and paying close attention to the road. Why, then, does the sign not say SLOW - TRAFFIC ENTERING HIGHWAY? For that matter, why did the highway department not lower the speed limit on that bit of road?

The sign is technically accurate. The hill does block the view. But out of all the information that drivers need about that bit of road, the author of the sign chose one of relative unimportance. The sign neither explains the hazard nor guides us to the correct action.

Road signs make Twitter look like Russian novels. They must be concise enough that a driver moving at highway speed can read, understand, and act upon them without being consciously distracted from the task of driving. Every word must be chosen with care. But this is not enough: Those carefully chosen words must express the right message. They must get to the heart of what is important about a road hazard.

We technical writers face the same challenge. Sometimes our readers need guidance to avoid hurting themselves, damaging the product, or losing data. In such cases, we need to tell them what consequence they need to avoid. It's not nearly as helpful to tell me that the machine may overheat if I operate it inside a cabinet as it would be to tell me that it may catch fire if I do that.

Sometimes our subject-matter experts do not make clear what the consequence of ill-advised action (or inaction) might be; in many cases, this is because they assume that anybody is able to understand the implications of the hazard. We need to ask them if they don't volunteer the information. "So, forgive me if this is a silly question; but what would happen if I put the machine in a cabinet and it overheated? Would it melt? Would it catch fire?"

Having elicited the information we need, we can wordsmith it into a form that will give our readers the information to prevent problems. That's the goal. That's always the goal when warning readers about anything. There's nothing so useless as warning people about things they can't change.

Hills have always blocked views and always will. But if we know about the hazards they hide, we can take steps to reduce the risk.