For autonomous vehicles, the hardest lessons to learn are the ones that can test the skills of even the most experienced human drivers: an errant cyclist darting through a red light, or an animal bolting into oncoming traffic from behind a corner. The Chinese tech giant Baidu has developed a new AI-driven simulator to prepare its Apollo robotaxis for just such rare but high-stakes road hazards, as the firm looks to gain an edge in the fast-growing self-driving taxi market. The system, Apollo...