Work Activities and Operational Errors at Selected Vessel Traffic Services

This report represents a preliminary step in characterizing work activities and operational errors at Vessel Traffic Services (VTSs) visited June-August 1996: Prince William Sound (PWS), Los Angeles/Long Beach (LA/LB), San Francisco (SF), Puget Sound (PS) and New York (NY). The focus was the watchstander involved in traffic management. Work profiles were characterized by examining video tapes of behavioral events in 15-min sample intervals. The times for logging and retrieving vessel data at PS and NY were two to three times those for the same functions at the other VTSs. For 13 shift and position change events, in which two watchstanders exchanged information about vessel traffic and operations, most occurred in less than 1 min. Seventeen VTS operational errors were detected. Most loss of situation awareness errors occurred at PS and NY, 5 of 7. The average total communication times were correlated with average workload estimates and may provide an index of increasing work activities in the VTS environment.