When Severe Typhoon Dolphin approached eastern China in August, more than 110,000 delivery riders across Hangzhou received automatic alerts and personalised safety guidance on their mobile phones every minute. With a few taps, Hangzhou’s “riders’ code” system navigated them to the nearest shelters, which authorities said had reduced their occupational risks under extreme weather. Behind the tailored and quick support was Hangzhou’s artificial intelligence (AI) urban management system, which had...