This Thursday, L.A. Metro's board will discuss whether to replace most of the sheriff's deputies who currently patrol its stations with police officers from Los Angeles and Long Beach.

A Metro report earlier in November recommended the change. It cited the low visibility of sheriff’s deputies and a lack of deputies to meet staffing demands.

L.A. County Sheriff Jim McDonnell defended his agency when discussing the proposal with Airtalk: "I know some of the challenges that are faced with visibility on the lines, the ability to respond quickly to calls for service on the lines. I think we've improved dramatically where we were on those issues. However, at the end of the day, it's a massive system."

The policing contracts are lucrative — worth almost $527 million over the next five years.

The move would affect more than half of the subway lines and 60 percent of Metro's bus service.

Since 2003, the LASD has been the only agency policing the Metro transit system. If Metro's board of directors makes the change, the new policing plan would take effect in January 2017.