First of all, every commuter rail system has full time maintenance crews, and they always have plenty of work: changing lightbulbs in the tube, fixing a signal that got bumped, replacing an on-track communication cable that was vibrated out of place and smashed, etc.

FORBES: Why Does BART Need To Do Nightly Maintenance?

City officials acknowledge that the open air cable cars, which ply only eight miles of track, produce a disproportionate amount of accident-related costs.

NPR: San Francisco Cable Car Accidents Costs Millions