The Viaducts of Atlanta were mainly created in the 1920s to bridge numerous level crossings of roads and railroads.
Atlanta being founded as a railroad city and ending up with at least six major lines entering the city, there were many places where human traffic encountered that on the rails. The first viaduct was just the Broad St. bridge which was rebuilt several times, most importantly the iron version built by Lemuel Grant in 1854 but longer viaducts were coming.
In January 1913 the Bellwood Viaduct was opened, allowing car and foot traffic to cross the railroad line parallel to Marietta Street to the west side of the city via Bellwood avenue (now Donald Lee Hollowell Pkwy.).