Is it just coincidence that the Heinz Company’s logo (a shield-shaped figure) is identical to that of the PA Turnpike symbol (a virtually identical shield-shaped figure)? Please note that the Heinz Co. is from Pittsburgh, and the Heinz family has been quite influential in PA politics, etc.
…Just a coincidence?
They aren’t quite identical. The Heinz emblem has a rounded top. The PA emblem is a keystone, for the “Keystone State”, a nickname which certainly predates the Heinz company. The typical outline they use on their products may have been influenced by it, I suppose.
If Heinz had influenced the PA highway markers, they would probably be in the shape of a pickle, and every route would be labelled “57”.
(See Cecil’s article on the origin of Heinz’ “57 varieties” slogan).
They’re not shields. They’re keystones. Pennsylvania is the Keystone state. You’ll find boatloads of Pennsy stuff with keystone motifs.
Woops. Simulpost, but the same conclusion. 
Ah, yes… The Keystone State! It seems a recent trip to Pittsburgh has me seeing Heinz logos everywhere! It was like an ink-blot test when I pulled onto the PA Turnpike headed home…
Ketchup bottles! Kecthup bottles! They’re eveywhere! Doc, all I see are ketchup bottles! - Jinx