Why Monorails Are A Bad Idea https://www.youtube.com/watch?v=9f__nhlHC1g A monorail is OK to go from one end of a line to the other. However, having several branches and junctions can be quite problematic.
How Los Angeles Rejected the Monorail https://www.youtube.com/watch?v=piF7adQyXCk
How Seattle Rejected the Monorail https://www.youtube.com/watch?v=VVQ-2lcBOjI A long double track monorail line might have worked for Seattle. However, conventional rail is still much more practical.
Why Tokyo's Metro Is Profitable and New York City’s Isn’t https://www.youtube.com/watch?v=HdJwAUdvlik
https://www.youtube.com/watch?v=D4YFFtTEUQc The Broadway subway in Vancouver, BC.