Why is the Shanghai-Yan'an Elevated Expressway so blocked?

The reasons for the traffic jam on the Yan'an elevated highway in Shanghai are as follows:

The number of private cars continues to grow? As people's living standards improve, more and more people begin to own private cars, resulting in increased pressure on road resources and increasingly serious traffic congestion.

Road construction does not match urban planning?. Although the construction of infrastructure such as elevated roads and subways has been strengthened in recent years, due to insufficient planning, some roads cannot meet the needs of a large number of vehicles, exacerbating traffic congestion.

The north-south elevated highway connects too many interfaces to other expressways? There are a large number of vehicles entering and exiting almost every entrance and exit of the north-south elevated highway, causing a certain degree of congestion at the rear.