{"nrhp_refnum":"98000713","name":"Davis Subway","other_names":["Richards Blvd. Undercrossing","Structure No. 75.45"],"category":"structure","location":{"address":"Richards Blvd. between Olive Dr. and 1st St.","address_restricted":false,"city":"Davis","county":"Yolo County","state":"CA","lat":38.54162998500004,"lon":-121.73989842299994,"geom_source":"nps_gis"},"listed_date":"1998-06-26","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A railroad grade-separation structure in Davis, Yolo County, California, where Richards Boulevard passes beneath the old Southern Pacific tracks. The steel I-beam railroad bridge and its road underpass were built in 1917 as part of State Route 6.","why_significant":"It is argued to be significant under Criterion A for its link to California's first state highway system under the State Highway Act of 1909, and as the only important engineering feature of State Route 6 still intact. Under Criterion C it is a rare, early Southern Pacific I-beam bridge, among the oldest in the state. It also has secondary significance as a segment of the Lincoln Highway.","narrative":"Richards Boulevard passes beneath the old Southern Pacific railroad tracks in Davis through a subway completed in 1917 and early 1918. Its single-span deck is made of twenty-eight 24-inch steel I-beams resting on two identical reinforced concrete abutments. The span is only about 28 feet long, and the deck was built 48 feet wide to carry three sets of tracks. A pedestrian and bicycle tunnel was added alongside in 1977. The structure was part of State Route 6, one of the first routes funded in California's state highway system, and the route was also labeled part of the Lincoln Highway. Most comparable pioneer-era highway subways were lost when roads were widened, but this one survived because Highway 40 was built on a new alignment south of town. It is considered one of the oldest remaining Southern Pacific I-beam bridges in California and still serves as a main entrance to downtown Davis.","period_of_significance":"1917 to 1943","architect_builder":null,"architectural_style":"Other: I-beam bridge","criteria":["A","C"],"status_note":"Still in use for rail, vehicular and pedestrian traffic; described as remarkably intact and serving as an entrance to downtown Davis.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:27.818873-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/98000713.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/98000713/0ad7453ffe-800.webp","url_1600":"https://nationalhistoricalregister.com/media/98000713/0ad7453ffe-1600.webp","licence":"CC BY-SA 3.0","author":"Brian Wickstrom","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Davis_Subway_-_Davis,_CA.jpg\" rel=\"noopener\">Brian Wickstrom</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Davis_Subway_-_Davis,_CA.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123862384","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q133571797"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/yolo-county/davis-subway-98000713/"}