You get the feeling that they're solving the wrong problem though. No-one can can predict what other people are going to do, and what other drivers do is also

You get the feeling that they're solving the wrong problem though. No-one can can predict what other people are going to do, and what other drivers do is also affected by what you do. Most drivers aren't even paying that much attention. Realistically you can't model that to any useful level of precision. I think maybe vendors are trying to build a more deterministic system that can justify its actions, but to make autonomous driving actually work, I suspect you have to make it drive like human: taking actions "confidently" (i.e. slightly recklessly) assuming the world will roughly follow a rational model, while also driving "defensively" to cope with the general unpredictability of reality. The price to pay for this strategy is familiar to human drivers: the occasional fender bender.