You might not have noticed the recent article in The New York Times reporting on the dispute between New York State and the federal government over highway signs.

New York takes the position that it should be able to post signs on major roads promoting tourism in the state, as in “I (Heart) N.Y.”

But the U.S. Department of Transportation has the view that the signs, according to the Times, are “out of compliance with signage rules because they are so big and crammed with words and information that they are dangerous distractions to drivers.”

While the dispute rages on—New York asserts its right to advertise its attractions; the federal government threatens fines or even more severe penalties—let’s discuss how this relates to your internal communication posters, electronic screens and other workplace communication.

Here’s the most common mistake communicators make in creating posters: including too much content. We should treat all workplace channels as the indoor equivalent of a roadside billboard—which calls for a strong image and a few compelling words.

But instead we write a message which is more like a short email than an at-a-glance experience. The result? Employees miss the message. They’re not going to stand and read the poster or screen; if they don’t get the meaning within a few seconds, the opportunity is lost.

That’s why we should pay attention to the federal government and follow these 3 rules for creating workplace communication:

1. Limit your message to one concept. One of the U.S. government’s complaints about New York’s signs is that each contains too many different concepts. This causes drivers to become distracted.
2. Choose a single arresting image. The poster isn’t a scrapbook; it’s meant to be experienced in one quick glance.
3. Display the poster just long enough for it to be noticed. After a few days (at most a week), it becomes wallpaper. So move it along.

As with every aspect of employee communication, creating effective posters requires thinking about how to use this particular channel for what it does best. That sounds simple, but it’s harder than it looks.