I know the real reason.

Why do ER billboards show wait times?

On the freeway I passed a billboard for an emergency room that said "Current wait time: 8 minutes" and I thought, "Gee, with a wait time like that now might be a good time to patch up this giant hole in my chest that's spurting blood all over the windshield."

I barely care what the time and temperature is, and I definitely don't care how long I could sit in a waiting room. Why not take that sign down and put up a screen that plays wildlife videos all day? And while we're at it, take down the hospital and put in a taco restaurant.

Free advice, emergency room. You're welcome.