Why are the urban planning of Chang'an, the capital of the Tang Dynasty, and Kaifeng of the Song Dynasty so different?

To be precise, the degree of development of the commodity economy is different.

Tang Changan was built on the basis of Sui Dynasty. The people of Northern Zhou Dynasty were relatively simple and did not know much about enjoying life.

The square shape is beautiful and easy to manage. It is open during the day and closed at night. No one is allowed to wander around. The separation of the markets makes it easier to manage, but it is not convenient for life. It is okay to travel half way across the city to the east and west markets to buy a horse or some jewelry. It’s annoying to have to travel so far to buy a needle, thread, salt, etc.

Dongjing in the Song Dynasty was a commercial city, and the convenience of water transportation (Bianhe River) was considered when building the capital.

Moreover, the commercial area and residential area are mixed, which greatly facilitates people's lives.

In the Tang Dynasty, there were no restaurants in the modern sense, only hotels (only selling wine, not vegetables). The catering industry in the Song Dynasty was already very developed, and so was the entertainment industry. Only the city gates are closed at night, and there are no square gates to close. There is also some nightlife at night.

Personally, I think the streets are strictly managed and the markets are open and lively to facilitate the people. The latter is more advanced.