The Patricia Miller Washington Metropolitican Area Transit Authority collection largely consists of photographs and maps documenting the the construction of the Metrorail system between the years of 1950 and 2000. The collection also includes WMATA publications, including flyers and newsletters, that provide updates on the progress of the construction of the Metrorail system.

The WMATA Metrorail Specifications collection is comprised primarly of technical specifications and contracts related to the construction of Metrorail. The collection consists of unbound letter-size documents, bound letter-size reports and specifications, oversize reports and specifications, and blueprints. The WMATA website was added in 2023 as part of GW's Web Archives Program.