I loved City Skylines, but never advanced far enough to have problems with the AI traffic, but I read over and over again that was a big late-game problem. Hoping that it's resolved in CS2, but this video didn't really answer the question. Hope we see some performance results from large-pop cities in the run-up to release.
Otherwise, the traffic accidents was a really neat inclusion!
And I think this is just a soundbite from a one-off question during an interview about many other things. It's perfectly understandable that he wouldn't answer a random question directly if he didn't know the answer or have an approved response.