US 29 and 70 Yadkin River Bridge (1951)

**This bridge has been replaced**

This 1951 deck girder bridge is an example of post-World War II highway construction that was meant to relieve bottlenecks as rapidly as possible with minimal investment. The structure was built to relieve traffic on the narrow two-lane Wilcox Bridge. In contrast to its ornate companion, it reflects post-war practicality and austerity. The five main spans of the bridge consist of a continuous run of two massive parallel girders, which in turn are comprised of steel plates riveted together. The beams are "haunched," meaning that there is a slight inward curve to them that allows a longer distance to be spanned with less material. The fact that longer spans could be built also meant that fewer piers needed to be constructed, which not only reduced labor costs but also allowed the piers to line up with those of the Wilcox Bridge, a consideration for flood control. It is a design, therefore, that relies on a reduced number of components, with these having a high degree of strength. However, due to the continuous design, there is a lack of redundancy, and if one pier or girder were to fail the entire bridge would likely collapse. This is why the continuous deck girder design fell out of favor, with remaining examples being targeted for replacement.

Unusual for a bridge of this style, this structure has the floor beams that support the road deck situated on top of the girders, as opposed to being strung between them. In all likelihood, this made the bridge cheaper and quicker to construct. A later deck girder bridge, the US 701 Southbound bridge over the Cape Fear River, does not employ this design. On the north shore there are two steel stringer spans which follow the standard 1950s template. The railings follow the boxy fence style that was used by the state from the 1940s into the 1960s.

Sadly, this bridge will be replaced at the same time as the nearby I-85 bridge. Even though it may not be a particularly attractive bridge, the curved profile of the beams have made it a more subtle companion to the Wilcox Bridge. In contrast, the modern bridge will be a highly standard beam bridge that will be indistinguishable from a freeway overpass.

Facts

• Year built: 1951
• Route Carried: US 29 NB, US 70 EB, and NC 150 EB
• Crosses: Yadkin River (High Rock Lake)
• Location: Davidson and Rowan Counties, NC
• Design: Continuous haunched deck girder with riveted connections
• Number of main spans: 5
• Total length: 873 ft.
• Inside width: 27.8 ft., two lanes
• Average Daily Traffic: 4000
• Sufficiency Rating: 32.1 out of 100
• National Bridge Inventory ID: 1590392
• Coordinates: 35°24'6.29"N, 82°48'33.24"W

Pictures

• L & C: two side views of the main spans. R: a view across the deck, facing south.