Be warned, would-be weekend commuters: Beginning October 6 there will be no Caltrain service at either of the San Francisco stations on Saturdays and Sundays. Bayshore Station will be the rail line’s northernmost weekend drop off until “late spring 2019.”

According to the Caltrain site, the weekend stoppage “is necessary to complete the San Francisco tunnel work, which will pave the way for Caltrain Electrification.”

Caltrain’s San Francisco section includes four tunnels. During the weekend work sessions, “crews will create additional clearance and install anchor bolts in the tunnel ceilings to facilitate the installation of the overhead contact system that will power the new electric trains.”

Right now there’s no particularly end date for the planned work beyond a general “late spring” window.

In the meantime, buses will move passengers between the SF Caltrain station at Fourth and King and the weekend Bayshore terminus. But “buses will run on a schedule different from the standard Caltrain weekend schedule, so plan for additional travel time.”

The multibillion dollar electrification plan is part of a long-planned Caltrain overhaul that the rail line promises will improve service by replacing diesel trains with electric ones that will take the route at 79 miles per hour and allow for more engines on the tracks at the same time during peak hours.

Under the current schedule, passenger service on the new trains would start around the beginning of 2022.