I saw this at UMASS Boston (my alma mater) for these pics. The bark was quite distinctive so I thought I'd post. Any guesses?
Bare Tree ID
Hmmmm, they didn't leave you any leaves did they? Does look familiar, but I am no help
Those look like a UMass planting of Thornless Common Honeylocust - Gleditsia triacanthos var. inermis.
Twigs, buds (in silhouette), branching pattern, form, bark, and frequency that one finds this plant in arrays such as you've shown - those are keys I observed.
It has been one of the more commonly planted deciduous species in urban situations, for a variety of reasons. It has small leaflets on compound foliage that provides filtered shade and creates less appearance of leaves to rake; it is quite tolerant of disturbed and/or compacted soils; it tolerates drought and reflected heat in urban situations; it is very easy to produce and transplant; it offers a gentle golden fall color; it is quite winter hardy.
It ought to be a law that one learns all these types of deciduous plants in the dormant season - it makes identification exponentially easier any other time (even over the internet around the world). If one is in the landscape or horticultural profession, it should be criminal NOT to be able to ID this way. You learn pretty quickly what you are being sold - or not - if you can identify it better than the nurseryman/salesman.
I did do my initial learning in winter (Still use the ancient reprint of Fruit Key and Twig Key by Harlow). I think VV is right, it really helps. But that was in Ohio, a million years ago, now with so many exotics planted everywhere, and living on the west coast, it's like starting over...
I sure wish there was some sort of global Fruit Key and Twig Key ;-)
You could do worse than one of Dirr's texts. He covers quite the gamut of Northern hemisphere species - especially ornamentals - with detailed descriptions of the ID features.
It is one sure way to make you learn the definitions of terms. You'll never forget what a tripartite thorn looks - and feels - like, especially when protruding from a thumb.