Hacker News with Generative AI: Beijing

The pigeon whistle: A defining sound of old Beijing (2019) (chinatoday.com.cn)
IF you have ever watched a movie that featured old Beijing, there is a good possibility that it contained a scene with a flock of pigeons flying over quadrangular dwellings (siheyuan), giving off a uniquely harmonic buzzing sound as they flew by. That sound is what local residents remember when they think of old Beijing.
Beijing plans to expand autonomous driving test area (news.cn)
Beijing plans to significantly expand its high-level autonomous driving demonstration area to approximately 3,000 square kilometers between the fourth and sixth ring roads, more than double the size of the city's six urban districts, an official said on Friday.