Surface spalling, even where rebar is exposed, is not that uncommon, especially in older structures. Advances in reinforced concrete design, and specific degeneration mechanisms such as D cracking and others, have come a long way since the early to mid 1900s.
It is important to draw a distinction between problems that need attention, and problems that may indicate imminent structural failure.
Solely regarding what is visible in your first image, that appears to be significant surface spalling, the rebar has been exposed, and that area would, in my opinion require close attention in the near future, and repairs as soon as possible.
The surface spalling is severe in your second image, but that does not concern me near as much as the apparant deflection visible, (bowed in the vertical plane to the right, maxima just above the lower arch), or the horizontal crack that appears across two full faces of the pier and could well extend through the entire depth of the pier. I believe I see cracking in both arches as well.
However tall that bridge is, times two, is the closest I’d allow myself or any member of my family to approach and even at that range, I’d want a hard hat, and a quick, “in and out” visit, and only for freasons of dire emergency.
That’s flat out ugly.
Southbridge 16, 2, 6, and 7 don’t inspire confidence either.
Well then, look at this one... This is the NY State Thruway Authority at work protecting our safety...Do you see that blue collar near the top of the pier on the concrete pier/leg nearest to us - someone HAS been working to 'protect our safety'.
It does look like some work is going to be required near the base of that pier sometime in the future though ...