The article brings up BART wheel/rail noise, which is an interesting window into SF’s unique and some might say self inflicted issues. It’s my understanding BA

The article brings up BART wheel/rail noise, which is an interesting window into SF’s unique and some might say self inflicted issues. It’s my understanding BARTs screech comes from statutorily over-powered brakes grinding flats into the wheels. The power rating didn’t take into account the fact that BART is both an all weather outside and an underground (dry) system. On wet outdoor tracks the indoors-only power brakes lock up and wear the wheels flat. In turn these flats grind periodic indents in the tracks, and the whole thing has a feedback loop which ends up in the entire track being corrugated and no wheel ever being truly circular. Solid axles (no differentials) don’t help either. Screeching and howling ensues to a level that is damaging to the hearing of passengers and staff alike.