Comment by bdamm
23 days ago
There are entire subway systems built with tire-on-concrete where the trains ride precisely the same routes down to the millimeter. Montreal’s is a famous one. These systems are not as efficient as rail, but they are quieter and gentler than the typical subway.
The problem is that the optical guided bus was built with the intention of reducing cost, since painting lines is a lot cheaper than building rails.
The moment you have to build rail-like things you lose most of the cost advantages.
That's still rail. It's just not steel-on-steel.
Otherwise you'd have to seriously limit what systems you call "monorail".