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Comment by krisoft | Hacker News Reader

I work at a self-driving car company and we observed a similar problem when we did some off-road testing on dirt tracks. The cars were too precise and they were cutting deep ruts into the soil. We too solved it by adding a pseudo-random offset to the track.

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I believe Google Maps adds a bit of a rng in which route it will recommend when two otherwise similar in distance/time. Obviously the traffic input also affects this, but that's a slower feedback mechanism; better to distribute the cars all leaving the airport for downtown across the 2-3 possible routes upfront rather than dumping them all onto route A until it's a jam and then all onto route B until it's a jam, etc.

Annealing.

I'm sure Google Maps has had to put their thumb on the scale in numerous instances. I recall reading articles about it "discovering" more optimal routes between Point A and Point B only to find things like the new "optimal" route being down a neighborhood street, and then the locals started squawking.

Before the current wave of automation there was a previous technology to automate buses using optical sensing and lines in the road which had the same issue.

If you want rails: build rails.

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.

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

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

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.

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