This style was prevalent in the 1950s/early 60s for bridges wider than 2 lanes - https://goo.gl/maps/aDshucV6LDpduxY6A
That ornate style along with a few other similar variants seems to have been the dominant style for a pretty long time in the 20th century for anything that wasn't a truss bridge, from around the 1900s-1950s I've noticed. The US 74/29 bridge over the Catawba River has that style of guardrail, built in 1933, as well as the Bearskin Creek bridge in Monroe on what used to be US 74 before the mid-50s. That one was built in 1922. US 17's Ashley River Bridge in Charleston (1926) also has that design.
My favorite execution of the ornate type guardrails are the ones on the Old Victory Bridge over the Apalachicola River, also built in 1922. The Old Trout River Bridge (1930) in Duval County, FL also has a similar design I like. I think there was another bridge in Jacksonville that had a similar style, and when it was replaced they kept the design in the new construction.