So I did a little testing and found out why I've never seen anyone use these driveway gates. It's because they essentially don't work, unless I'm missing something obvious.
When I install these gates over a fence the way one would normally install a fence gate, the fence graphics do not disappear. Instead, the fence graphic as well as the gate graphic are both visible. This obviously doesn't look good.
On the other hand, if I leave a 5-square gap in my fence and place the gates into that gap using the
moveobjects on cheat, it looks good but the gates subsequently cannot be locked.
The above test results are valid regardless of whether a driveway is added or which of the OP's four fences I tested. I should also point out that a careful look at the OP's picture shows that they apparently did not actually place these gates atop a driveway.
So here are the pictures.
Here's what it looks like when I placed the "pig-pen" gate into a gap inbetween the Maxis "Tornado" fence (the closest aesthetic match), using
moveobjects on. It looks good, but unfortunately will not lock (because there was no actual fence), which defeats the entire purpose of the fence and gate:

Here's what it looks like when I placed the gate in the normal manner, right atop the fence. While this methods results in the gate being lockable, the fence is still visible, which doesn't look good and is hardly worth using the extra custom content:

At this point, my own easy tutorial on constructing fences and gates across driveways (
here) still achieves what these gates don't and do not require any custom content.