Only in Louisiana

The sign over the Lake Pontchartrain Causeway, reminding people to use their blinker.

The causeway connects Mandeville, LA on the north shore with New Orleans on the southern shore.  The causeway is 23.8 miles long.  Back in the day, barges used to slam into it, knocking it into the water, although we only hear about that infrequently now.  However it still causes one helluva mess.