Far more busses operated in Chicago/NYC etc in 1970 than streetcars in 1920.
What happened is busses took over and street traffic increased. On otherwise empty streets a buss network could be far more convenient than subways, but that’s not the world we live in.
It’s mostly stoplights and the need for them that makes streetcars and busses suck relative to subways.
Subways will always tend to be faster, just because they don't have cross traffic enforced by cycling traffic lights. Traffic lights are just a reality of street-based transportation, because the light length needs to be long enough that someone like a grandma with mobility issues needs enough time to cross the street.
Traffic lights can be tied to bus traffic - if a bus approaches give it way (both by letting other traffic flow away as well as keeping green till the bus crossed) Doesn't work for all situations but can give 80% green wave, even where bus lines cross.
However then bus is still slower than a subway on long distance. A subway can take a more or less straight line, while busses have to follow roads. Also passengers typically expect denser stops with busses. Also by being alone on the track a subway can go faster as max speed.
But even with subway on long distance, bus can connect with high density to subway, so that more people can reach the station.
> On otherwise empty streets a buss network could be far more convenient than subways, but that’s not the world we live in.
I live in a world with relatively good subway system for travelling across the city and a relatively dense bus system to solve "the last mile" thus quite a good combination. (While the system is close to collapse due to missing investment over also few decades and new projects being too slow in completion)
> Far more busses operated in Chicago/NYC etc in 1970 than streetcars in 1920.
Different times, the system now evolved from a state where streetcars were removed so they can't be compared in that way. Chicago/NYC was a very different place than it was in 1920, itself would change in ways because of a bus system vs streetcars.
What happened is busses took over and street traffic increased. On otherwise empty streets a buss network could be far more convenient than subways, but that’s not the world we live in.
It’s mostly stoplights and the need for them that makes streetcars and busses suck relative to subways.