Completed in 1898, the Vacy Bridge is an early example of an Allan type timber truss road bridge and in 1998 was in good condition.
As a timber truss road bridge, it has many associational links with important historical events, trends, and people, including the expansion of the road network and economic activity throughout NSW, and Percy Allan, the designer of this type of truss.
Allan trusses were third in the five-stage design evolution of NSW timber truss bridges, and were a major improvement over the McDonald trusses which preceded them. Allan trusses were 20 per cent cheaper to build than McDonald trusses, could carry 50 per cent more load, and were easier to maintain.
The Vacy Bridge is located in the Hunter region, and it gains heritage significance from its proximity to the high concentration of other historic bridges in the area.