Standardization of design and economy of construction were hallmarks of the North Carolina highway system. This was particularly true in the area of maintenance, which was considered as important as new construction by the State Highway Commission's first chairman, Frank Page.
In 1921 Page established the Bridge Maintenance Unit. The word "maintenance" was somewhat misleading because the work crews probably built as many new bridges as they repaired existing ones. The Bridge Maintenance Unit did not undertake much heavy construction, but it had the capability to build simple, straightforward, economical bridges with a minimum of equipment.
The availability of the unit for new construction was seen initially as a check on price gouging by private contractors, but it had the further advantage of centralizing design, construction, and maintenance
In 1931 the Bridge Maintenance Unit found its role greatly expanded as it took on the job of maintaining the 15,000 bridges taken over from the old county road system. By 1936 it employed more than 900 workers in crews across the state. The unit adopted standard plans for timber and steel stringer bridges and steel girder-and-floorbeam bridges.
From the late 1940s to 1960s, the Bridge Maintenance Unit steadily and systematically replaced most of the old county-built bridges on the secondary road system.