Can be downloaded here: http://trt.trb.org/trt_download.asp
A system for classifying industries. Established in 1937. Similar to and generally superseded by the North American Industry Classification System (NAICS). Still used by the Occupational Health and Safety Administration (OSHA) and by the U.S. Securities Exchange Commission (SEC).
The North American Industry Classification System (NAICS) is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy.
The Transport Canada Thesaurus (TCT) has been developed as a specialized controlled vocabulary to be used as a source of standardized terminology for the indexing and retrieval of Transport Canada information resources.