Federal prisons are failing to notify crime victims and witnesses when inmates are allowed to travel by themselves for medical treatment, the Justice Department inspector general said Thursday.

The federal Bureau of Prisons expects it will take until 2017 to require the notifications because it will take that long to negotiate the matter with the union that represents federal corrections officers, Inspector General Glenn Fine said in a report.

The timeframe is "excessive and unacceptable," Fine said.

The Bureau of Prisons proposed a revised furlough policy in 2003, but it has yet to be negotiated with the American Federation of Government Employees (AFGE) National Council of Prison Locals, Fine's report said. The agreement between the union and the agency specifies how policy proposals are negotiated, including that they generally are handled in the order received, the report said. It noted that 50 policies are awaiting negotiation.

More than 18,000 inmates over three years have been given permission to leave federal prisons unescorted to get medical treatment. The report says 6 inmates escaped rather than return to prison.

Prison and union officials did not immediately comment.