The merging of these databases formed the world's largest and most comprehensive bibliographic resource on transportation research information.
As of July 2020 TRID contains more than 1.25 million records of published and ongoing research, covering all modes and disciplines of air, ground, and water transportation—books, technical reports, conference proceedings, and journal articles.
The records in TRID are indexed with a standardized vocabulary from the Transportation Research Thesaurus (TRT) which has integrated both the TRIS and ITRD thesauri.
Among the professional disciplines from which documents in TRID arise are: public planning, management, finance, design, engineering, construction, materials science, environmental issues, safety and human factors and ergonomics, and operations.
[2] The TRID database publishes monthly an update of the more than 800 serials from which articles arise.