<<I've been meaning to check into the bumper height requirement for PA.
I have a vague memory of seeing a sooty, yellowed inspection chart at a
garage years ago which called out a required bumper height. This
especially comes to mind whenever I pull into a parking spot next to a
monster truck wannabe (or Expedition) and find myself looking up at its
door handles.
George>>

Your short changing the bumper height  issue Georgie.

The FOMOCO Expedition is low man on the totem pole.

How bout the IH Tonka Toy PU truck made out of a S series  class 6
straight truck?

You can walk under that.

But this is all state issues, bylaws etc.

The white refector's are a federal DOT issued rules of the road.
Look at the tail light reflector's on the back of the Van, or the
headlights.

You'll notice a couple of letter's engraved in them.

DOT.

Wonder what that is all about?