On our last road trip (in October), I told DD how to make the signal to truck drivers to blow their horns.  She wasn't successful then, but she remembered and tried again during our trip this Thanksgiving, again unsuccessfully.  I remember this being commonly done, with response, when I was a kid.  Do truck drivers not do this anymore?

The picture was taken in the lobby of the Hilton where we stayed Thanksgiving night.  Since the fireplace was on, DD was (appropriately) concerned with getting too close.  She's wearing her Dora swimsuit & cover up while we waited for the maintenance man to check & treat the indoor pool.