In response to your letters to the editor,
this photo can provide a mnemonic device:
This bridge is open, open to boat traffic on the intracoastal waterway.
Open like an open loop – which does not loop at all until it is a closed loop.
When the draw bridge is closed you can drive across it. If it were open you’d drive through the opening into the drink. Some people drink and drive over open draw bridges; they often drown.

These definitions apply to draw bridges. If the bridge is not a draw bridge then the terms are reversed. A closed bridge may have a “Bridge Out” sign on it if it’s not a draw bridge. If it is a draw bridge then the closed draw bridge be open to autos.

Get it? Didn’t mean to blow your mind.
Need another session
with Doctor Half-Explain-Everything?
Happy April 20th, 4/20.
what were you doing last year at this time?