SEPTA’s anticipated changes to transit services amid the coronavirus pandemic will begin Sunday, the transportation authority announced Thursday.

Service reductions are coming to buses, subways, trolleys, and the Norristown High Speed Line. Changes to Regional Rail schedules, prompted by plummeting ridership and staffing issues, began this week.

“We want to have service available for those who absolutely need it, but we also want to stress that if you do not have to travel, please stay home," said Scott Sauer, SEPTA assistant general manager for operations, at a city news conference Thursday. "Leave these services for essential workers and those who need to use essential services.”

Beginning Sunday, transit services will run on a Saturday schedule throughout the week until further notice. The Market-Frankford and Broad Street Lines will operate 24 hours a day. Both lines “provide critical services for essential workers and those who need to access medical care,” according to SEPTA.

Changes were prompted by “an effort to maintain a safe environment for customers and employees,” according to SEPTA. The authority is grappling with a nosedive in ridership as more people are staying home to maintain social distancing. Ridership figures have dropped about 60% on transit and 80% on Regional Rail compared with an average weekday.

NJ Transit and New York’s Metropolitan Transportation Authority are seeking bailout funds while facing drops in ridership — an option “on the table” for SEPTA, Sauer said.

Some bus and train operators will be “repositioned” to help with enhanced cleaning as part of the changes SEPTA is making. It’s also removing wherever possible buses that have cloth seats instead of molded plastic. On Friday, SEPTA will close outlying Regional Rail ticket windows and waiting rooms.

Willie Brown, Transport Workers Union Local 234 president, wasn’t satisfied with the new schedules or the steps SEPTA is taking to protect operators. “SEPTA’s more concerned about having equipment on the street than the safety of its employees," he said.

Earlier this week, SEPTA outlined refund and credit options for some riders who purchased weekly and monthly passes rendered useless as they stay inside.

PATCO has also adopted changes to its schedule, running trains every 15 minutes from 5 a.m. until 9:30 p.m. Ridership on the High-Speed Line was down about 74% Tuesday and about 61% Monday from its year-to-date weekday average.

At Monday’s news conference announcing the Regional Rail changes, Sauer said: “In my 30-year career, I’ve never seen a more challenging event than what we’re faced with today.”