The company I work for maintains a stretch of interstate and today I was sent to spray some weeds that had popped up in a couple of median beds we had planted. Now we maintain about a mile and a half of the landscape around an exit and the next exit on the southern side is 7 miles away. The median has catch cables along the median that switches sides every so often. It just happens that the cable runs next to the SB lanes for a couple miles after our exit so instead of going to the next exit to turn around, I just used the one when the cables switch sides. A cop saw me do this and proceeded to lecture me about how he had lights and I wasn't technically in an authorized vehicle to do that. He also decided that I wasn't worth the effort of giving a ticket after I told him that a copy of our contract was at our office and I could have it brought out to me if necessary.
TL;DR: I used the "authorized vehicle only" turnaround in an interstate median and got harassed by a cop for doing it.