The Full Form of TBR is‍ Transportation Research Board.

TRB is one of seven program units of the National Academies of Sciences, Engineering, and Medicine, which provides independent, objective analysis and advice to the nation and conducts other activities to solve complex problems and inform public policy decisions. The Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. TRB’s varied activities—described below—annually engage more than 7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest by participating on TRB committees, panels, and task forces. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation.

The mission of the Transportation Research Board (TRB) is to promote innovation and progress in transportation through research.  In an objective and interdisciplinary setting, TRB facilitates the sharing of information on transportation practice and policy by researchers and practitioners; stimulates research and offers research management services that promote technical excellence; provides expert advice on transportation policy and programs; and disseminates research results broadly and encourages their implementation.

TRB was established in 1920 as the National Advisory Board on Highway Research to provide a mechanism for the exchange of information and research results about highway technology. Renamed the Highway Research Board (HRB) in 1925, the organization accomplished its mission through standing committees, publications, and an annual meeting. In the decades that followed, HRB steadily increased in size. Information exchange remained its sole mission until the 1950s, when it began to undertake management of ad hoc research projects. The first continuing research management activity—the National Cooperative Highway Research Program— started in 1962. During the 1960s, the Board’s activities became increasingly multimodal in outlook. In 1974 the Highway Research Board became the Transportation Research Board. Since then, TRB’s portfolio of services has expanded significantly—first in the early 1980s, when it began conducting studies of national transportation policy issues, and again in the 1990s, when Congress, the U.S. Department of Transportation, and the state departments of transportation asked TRB to undertake additional tasks, including management responsibilities for the Transit Cooperative Research Program, guidance of ongoing research programs such as the Long-Term Pavement Performance studies, and management of the Innovations Deserving Exploratory Analysis programs.  More recent additions have included new cooperative research programs in airports, freight, and hazardous materials transportation, and the second Strategic Highway Research Program.