The Pipeline and Hazardous Materials Safety Administration is required by law to respond to safety recommendations issued by the National Transportation Safety Board (NTSB), an independent federal agency charged by Congress with investigating transportation incidents. Recommendations usually address a specific issue uncovered during an investigation or study and specify how to correct the situation.

Open Recommendations

The NTSB classifications for open recommendations:

OAA - Open Acceptable Action
OAAR - Open Acceptable Alternate Response
OUA - Open Unacceptable Response
ORR - Open Response Received
OAR - Open Await Response
IRR - Initial Response Received

Mode

A - Air
H - Highway
P - Pipeline
R - Rail

NTSB's CAROL site

To learn more, please access NTSB's safety recommendations data base CAROL.