The issue becomes the government's responsibility to enforce highway safety versus a right to practice religion, i.e., a "religious stance" by a well-known strict religious sect.
I wonder if the lantern can be seen as far away at night as can the triangle? It seems like the man was trying to accomodate safety.
I can see the objection to the triangle - with obvious references to pyramidology - most notably JW's -
Charles Taze Russel is in fact buried underneath one.