11870b5d_oric_Significance_Rating__HSR___Description
[HSR] 1 [Examples] 1960s pre-stressed concrete or steel stringer bridges. Small 1940s-1950s steel stringer bridges. [Description] 
Bridges barely old enough to be considered historic. Generally included because they retain remarkable historic integrity or are the last in a region.
HistoricBridges.org - Historic Significance Rating (HSR)
Description