Trains will no longer operate between 12 a.m. and 4:30 a.m. Monday through Friday.
All stations and concourse areas will also be closed during that time.
ALSO SEE: PATCO modifying overnight service for maintenance | What you need to know
This is phase two of a plan to address safety and hygiene concerns.
They're also working to improve conditions for staff, and provide a better overall experience for riders.