> such as L.A. and Denver, are watching transit ridership decline across the board, in part because investment in buses has trailed so far behind the commitment to trains
That's not completely true for LA (and for the record, train ridership in LA is on decline as well, while the population is growing).
Here's the actual reason http://www.latimes.com/local/lanow/la-me-metro-homeless-2018...
"People looking for warm, dry places to sleep have barricaded themselves inside emergency exit stairwells in stations, leaving behind trash and human waste. Elevator doors coated in urine have stuck shut. Mentally ill and high passengers have assaulted bus drivers and other riders."
"More than 1 in 5 current passengers has been harassed on the train. In a 2016 survey, 29% of former riders told Metro they stopped taking transit because they felt unsafe."
"Sim said she saw a man pull down his pants, squat over the edge of a platform and defecate onto the train tracks at Union Station. She said she has sat in urine on the subway, “hopscotched through peoples’ feces” on sidewalks, and endured verbal and sexual harassment on the train."
"In one more serious case, Loew said, LAPD officers used a Taser on a man who was brandishing a knife and threatening passengers."
"He kept riding, until he sat down one morning on a seat that was wet and hot with urine. With no change of clothes on hand, he wore the urine-soaked pants to work. Then he started driving to work again."