I was watching this video of a live chicken trapped on a moving truck and thought it was strange that it’s not possible to say anything to them even when circumstances might warrant it. All we got is honking and waving. There could be a touchscreen interface with a map of nearby vehicles. It could be voice controllable or the passenger could do it for safety.
In a dense crowd, the information being exchanged amongst the crowd is enormous. It is a constant negotiation, of different parties trying to get somewhere but also trying (hopefully) to respect other people’s space. And the stakes are lower, because bumping into someone is fine at 1 kph but totally unacceptable at 50 kph. And humans are dynamically adjustable, like raising ones arms so that a stroller can pass more easily. Cars can’t really do that (except Transformers: Robots In Disguise).
In a crowded bazaar, the bandwidth from reading people’s facial cues, from seeing whether they’re distracted by goods on display or from their Instagram posts, plus what people actually say – and what they don’t say – and how quickly or slowly they walk. All of that is context that is necessary to participate in the activity of passing through the crowd, and I think that cost-optimized technology to exchange the same amount of info while also needing to react 50x faster and deterministically, with safety standards suitable for 2-tonne machines that already kill and maim thousands per year, that’s not really feasible.