Up to one-third of the 12,000 inmates in Los Angeles County jails can’t get to their court appearances because of a shortage of functioning buses, and county supervisors this week advanced a proposal to try and fix the problem.

The LA County Sheriff’s Department currently has only 23 operable buses out of a total of 82, and there have been days when as few as six were running, supervisors said.

Officials said the breakdown of the inmate transportation system has kept the county’s seven jails overcrowded with incarcerated people who might have been released by a judge or sentenced to a state prison — if they had appeared in court.

“Transportation should not be a barrier to administering justice. Having individuals sit in our jails because we can’t transport them to court is simply unacceptable,” Supervisor Lindsey Horvath said.

The Board of Supervisors voted unanimously Tuesday to implement an interim plan to get more working buses running from jails to courthouses and medical appointments. It includes borrowing vehicles from neighboring counties and asking the California Department of Corrections and Rehabilitation to help transport inmates to state prisons.