[bdamm]

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.

[bobthepanda]

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.

[namibj]

That's still rail. It's just not steel-on-steel.

Otherwise you'd have to seriously limit what systems you call "monorail".