I’m on a recumbent trike until my shoulder gets more strength back. I rode the Hump bridge a week or so ago. Walking or carrying the trike isn’t much of an option. I just waited till I had room to roll across it without annoying too many people. The chicanes are quite a bit of fun on the 3-wheeler. Good opportunity to lift a wheel and ride it like a bike. 
Honestly it is about the same width as the underpass that goes under Memorial bridge. Problem is that if you get it wrong, you’re face to face with oncoming traffic on GW Pkwy.
I’m heading south to Alexandria on my commute home tonight. I’ll report on how fat it is.
Pete