SAN FRANCISCO (CBS SF) – A San Francisco Municipal Railway spokesman said bus service is operating on schedule Monday on the first day of the new school year after the city’s school district warned that bus driver shortages could cause delays.

A message on the San Francisco Unified School District website said, “An operator shortage has resulted in Muni delays across San Francisco, which Muni is working on addressing. Students and staff who ride Muni may experience delays getting to and from school.”

Muni spokesman Paul Rose said Monday morning that bus service has been “operating as normal” today, the first day of the 2018-19 school year.

On Friday, Muni officials learned that 72 operators are going to make the transfer from working part-time to full-time, allowing the agency to add more than 700 additional service hours daily, Rose said.

Although the school district partners with school bus service First Student Inc. to provide yellow-bus service to and from each school, many district students ride Muni buses.

Muni officials estimate that half of the school district’s 57,000 students use public buses or light-rail to get to and from school each day.

© Copyright 2018 CBS Broadcasting Inc. and Bay City News Service. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.