The Netherlands will in 1998 establish a unified national transport safety board (TOR is the Dutch acronym), responsible for air, sea, inland waterway, railroad, and road transport. The TOR will have two primary tasks: (1) conducting independent investigations of transport accidents and incidents ("events"); and (2) recommending ways of mitigating threats to safety. Under the new TOR, there will be four "chambers" ("kamers" in Dutch) with responsibility, respectively, for air, railroad, and water transport. RAND Europe conducted an analysis to characterize the work of safety boards to enable comparisons among existing and proposed organizational structures, identify candidate structures for the TOR, and compare these candidate structures. The authors compare two possible models for the TOR: (1) a federated TOR in which the four kamers operate with great independence; and (2) an integral TOR that merges the diverse modality-specific investigative expertise of the kamers with a more global safety systems expertise. Although both models are feasible and would represent an advance on the current status, the integral model — although more difficult to implement — makes a major advance in transportation safety.