TRIS' focus is transportation research. TRIS does not contain information on vehicle standards and specifications, patent information, market research, or military transport.

Besides the material that is indexed and abstracted at the Transportation Research Board, TRIS receives records from several sources:

TLIB

TLIB Records are bibliographic records received from major transportation libraries. These citations generally do not have abstracts but they cover journals and publications that would not otherwise be covered in TRIS. The Harmer E. Davis Library at the Institute of Transportation Studies at the University of California, Berkeley provides monthly updates of journal articles and technical reports. The Transportation Library at Northwestern University provides quarterly updates of selections from its TRANWeb database (a database of journal articles and papers on transportation and law enforcement). Plans are to increase TLIB coverage by obtaining cataloging from other major transportation libraries.

EIS

Over 19,000 Environmental Impact Statements from the EIS Database produced by The Transportation Library at Northwestern University were added to TRIS in 2007. TRIS now contains records for the largest collection of Environmental Impact Statements in the world.

ITRD

The International Transport Research Documentation (ITRD) database is a cooperative bibliographic transport research database that contains more than 300,000 bibliographical references on transport research literature from 20 countries. There are 4 official languages represented in the database, English, French, German and Spanish. ITRD provides monthly updates of English language international publications to TRIS. These records are not included in TRIS on TRB’s Website.