The National Transportation Safety Board (NTSB) was established as part of the USDOT in 1966. It became an independent agency in 1975. It investigates accidents involving aircraft, highways, boats, railways, and pipelines.
The Government Documents collection includes the following (NTSB) series:
Report NTSB-AMM (TD 1.109/16:) Brief reports of accidents in civil and general aviation.
Railroad accident reports (TD 1.112/5:)
Marine accident reports (TD 1.116:)
Highway accident reports (TD 1.117:)
Pipeline accident reports (TD 1.118:)
Government Documents also has many general publications, handbooks, manuals, and other material from NTSB. In addition, we have many Congressional hearings and documents about transportation and pipeline accidents.