{"nrhp_refnum":"80003060","name":"Ida Street Viaduct","other_names":["Ida Street Bridge"],"category":"structure","location":{"address":"Ida St. between Monastery and Paradrome Sts.","address_restricted":false,"city":"Cincinnati","county":"Hamilton County","state":"OH","lat":39.10542658800006,"lon":-84.49448083799996,"geom_source":"nps_gis"},"listed_date":"1980-11-28","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["local"],"summary":{"what_it_is":"A reinforced concrete arch viaduct on Ida Street in the Mount Adams neighborhood of Cincinnati, Ohio. It crosses Wareham Drive between Monastery and Paradrome Streets and was built in 1931 to replace an 1882 wooden trestle.","why_significant":"The nomination argues the bridge embodies an innovative 20th century engineering and design scheme, with indirect lighting recessed into the hand railings. It was the first use of this type of lighting, and the system was later adapted for the Western Hills Viaduct. It is also described as the only one of Cincinnati's major concrete viaducts left unaltered, and as a prominent hillside landmark.","narrative":"Ida Street Viaduct is a 592-foot reinforced concrete bridge in Cincinnati's Mount Adams neighborhood, carrying Ida Street 44 feet above Wareham Drive. Completed in 1931 at a cost of about $90,000, it has two ribbed arch spans of roughly 138 feet each, with three small spans at either end, pylons atop the piers and a fluted railing. It replaced a wooden trestle built in 1882 for the incline railway company. Its main claim to attention is the lighting: 33 two-hundred-watt lamps recessed into the railings, fitted with lenses that spread light across the roadway and direct it upward. This was reportedly the first such installation, and the idea was later used on the Western Hills Viaduct. Structural engineer J.R. Biedinger is credited with the work, though credit for the artistic concept has been disputed. Streetcar tracks were removed in 1949, the only alteration, so the original design and lighting survive. It is one of eight major concrete viaducts in the city.","period_of_significance":"1900- (specific date 1931)","architect_builder":"Engineer, J.R. Biedinger","architectural_style":null,"criteria":[],"status_note":"Publicly owned and in use for transportation. The upper deck is described as greatly in need of repair because of heavy traffic.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:12.649368-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/80003060.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/80003060/34367953e0-800.webp","url_1600":"https://nationalhistoricalregister.com/media/80003060/34367953e0-1600.webp","licence":"CC BY 3.0","author":"Photo by Greg Hume (Greg5030)","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:IdaStViaduct.jpg\" rel=\"noopener\">Photo by Greg Hume (Greg5030)</a>, <a href=\"https://creativecommons.org/licenses/by/3.0\" rel=\"license noopener\">CC BY 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:IdaStViaduct.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71989219","wikipedia":"https://en.wikipedia.org/wiki/Ida_Street_Viaduct","wikidata":"https://www.wikidata.org/wiki/Q5987204"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/hamilton-county/ida-street-viaduct-80003060/"}