OK, sure, this is an excuse to post a video about fire apparatus, especially tractor-drawn aerials. And if into the comments section you go, aside from the pain you will find, there is some criticism that the chauffeur of the tower ladder (the one that doesn’t bend in the middle) probably wasn’t very experienced operating that apparatus. Maybe so.
Nonetheless, neither vehicle had much trouble with very narrow streets. Backing out? Yes, but not getting to the fire building.
I poked around on the NFPA website but could not find standards for minimum street widths and turning radii that were specifically intended for public streets. In NFPA 1, Fire Code, I did find standards for Fire Department Access Roads in Chapter 18.2.3, but that seems to apply to roads specifically intended for fire department access and not necessarily public streets. Those require 20′ minimum unobstructed width and 13’6″ minimum vertical clearance. The standard leaves minimum turn radius up to the authority having jurisdiction (“AHJ”). Remember, too, that NFPA standards and codes only have legal force when the AHJ says they do because they’ve adopted them as a municipal ordinance.
I did find this, though: http://www.nfpa.org/~/media/files/research/research-foundation/foundation-proceedings/next-five-years/wren.pdf?la=en which is a slideshow that talks about meetings between CNU and the Austin, Texas, Fire Department. Not much here, but I probably need to do some more research.