This collection documents the activities of the Citizens for Environmental Planning Today and Tomorrow (CEPT), a group of Baltimore County residents focused on development issues related to the Chestnut Ridge-Greenspring Valley area of the County, between 1975 and 1984. Materials are mainly textual and include minutes, correspondence, environmental statements, business manuals and directories, engineering design standards for housing and traffic.

The Light Rail Collection documents the planning, public citizens' response, public hearings, and research regarding Baltimore's Light Rail system, local public transportation options, and the Northeast Corridor Transit plans. The collection includes correspondence, publications, reports, meeting minutes, research files, and newspaper clippings related to the development and construction of Baltimore's light-rail public transportation system.