11870b5d_oric_Significance_Rating__HSR___Description
[HSR] 8 [Examples] Large, multi-span pin-connected truss bridges, older pin-connected highway Pennsylvania trusses, Whipple trusses, pin-connected Pratt truss bridges that are pre-1880. Large concrete curved chord through girder bridges with excellent historic integrity. Pre-1850 stone arch bridges. Highway truss swing bridges. Older suspension bridges. [Description] 
Extremely rare truss bridges fall into this category, as well as uncommon truss bridges with remarkable historic integrity, or extremely old examples of their type. Bridges with unique design characteristics, or high levels of ornamentation. Generally, bridges at this level will be recognized as historic by the government, but may not be preserved.
HistoricBridges.org - Historic Significance Rating (HSR)
Description