TRIDIndexes over 1 million records of published transportation research from books, technical reports, conferences and journals. Covers the planning, finance, design, construction, environmental issues, safety and operation of all modes of transportation--aviation, highway, marine, motor carriers, pedestrians, bicycles, pipelines, railroads and public transportation. The index is a combination of records from the former TRIS (Transportation Research Information Services) and ITRD (International Transport Research Documentation) databases. Many government documents link to fulltext.