Rinker Design Associates, P.C. (RDA) is a Virginia-based engineering firm with locations in Manassas (main office), Fredericksburg, and Richmond, Virginia. RDA has been providing professional services throughout the Northern and Central Virginia area for over 30 years. RDA is a Virginia-Certified Small Business, and a leading provider of professional civil engineering, transportation engineering, infrastructure design, traffic engineering, environmental, surveying, land planning, litigation support, and permitting services to both the public and private sector. RDA has also recently added construction administration, and Right-of-Way/easement acquisition and appraisal services within their range of capabilities, as part of their vision to provide comprehensive services for their clients.