CPKC Wilson Avenue Bridge (Portage Park)

Located in the Portage Park neighborhood of Chicago, this concrete slab bridge carries the Metra Milwaukee District North over Wilson Avenue. In the late 19th Century, the numerous grade crossings throughout the city represented a hazard to the general public. In response, the City of Chicago passed numerous ordinances, requiring the elevation of freight railroads within city limits. By the 1920s, major railroads within the core of the city had been elevated. At street crossings, subways were constructed to carry railroads over the roadway. An ordinance was passed on December 29, 1913, requiring the elevation of the Milwaukee Road line between a previous track elevation project at Irving Park Road and Elston Avenue. With the requirements, the city allowed for a lenient completion date of July 1st, 1927. However, work on the project did not begin until that year, starting with the two ends. Work was finally completed in 1929, completing the track elevation of this line through Chicago. Typical of 20th Century track elevations, the line was constructed with concrete retaining walls, and was generally constructed for two tracks.

The bridge at Wilson Avenue uses a typical design for this track elevation project, with four concrete slab spans, constructed in 1927. The main spans of the bridge are 22 feet in length, while the approach spans of the bridge are 13 feet in length. The entire bridge is set onto concrete substructures, and the bridge runs at a slight skew. The piers of the bridge utilize a typical design for the era, utilizing concrete columns connected by arches. This particular design was standard for most railroads throughout the United States, and provided a decorative aesthetic to bridges in urban areas. The bridge was originally constructed for two tracks, and continues to serve two tracks. The bridge was likely constructed by railroad forces, as was typical for this railroad company. The Milwaukee Road was known for minimizing contract bridge projects, using company labor where feasible. This design of bridge was commonly used by railroads, due to the ease of construction and durability. Overall, the bridge appears to remain in fair condition, with some minor deterioration noted on the substructures. However, the superstructure appears to be in better condition than similar bridges of a similar age, with very little deterioration noted. The author has ranked the bridge as being locally significant, due to the common design.