Ice and cockeyed driving

I had to run a couple of errands this morning. This in itself is no great thing. Gets me out of the house. Occasionally I see some odd signs while I am wasting gas and time on the road. As I drove along I'm taken aback by a road hazzard sign. Not slippery when wet, which is what I would expect here in Houston, but beware of ice on bridge. Uh, it's 90 degrees outside! Ice on bridge? Did I suddenly get transported to North Dakota? I thought the sign was funny cause this part of town rarely ices over. While the temperature occasionly dips below freezing during winter, it may last all of a day. But the sign did strike me funny after all the weeks of near 100 degree heat. Then I saw a how's my driving sign on the back of a company pickup truck. This really is not odd. Companies all over use these signs. I dont know if the companies are trying to intimidate their drivers or if they really want other drivers to call and report an unsafe driver. The odd thing was that the sign was crooked! What does that say? Does the company really care? Did the driver slap the sign on in a hurry? If the sign is crooked, does the driver drive crooked?