The MBTA will cut services this winter as a result of a worker shortage, it announced Tuesday.
Officials say the MBTA can't find enough bus and train operators to keep everything moving, and that more people are leaving than it can hire.
Effective Dec. 19, about one in every 20 scheduled bus trips will be dropped, the MBTA said.
Off-peak service on the Mattapan Trolley will increase in frequency from every 23 minutes to every 13 minutes in the late evenings on Saturdays and Sundays, but schedules during peak weekday periods will be reduced.
"This will change the peak frequency from every five minutes to every seven minutes" on weekday mornings and evenings, the MBTA said in a statement Tuesday.
There will be no change in service to the busy Green, Red, Blue and Orange Lines, according to the MBTA.
The organization says it is working to streamline its hiring process, with hundreds of open positions. There is a particularly high need for bus drivers.
The MBTA will hold a virtual meeting about the cuts Wednesday at 6 p.m.