Why can't Jiangyin Furong Avenue be elevated all the way?

There are tunnels. According to the watermelon video query, Jiangyin Furong Avenue cannot be elevated all the way, which is caused by the tunnel. From 80 yards of overhead to 60 yards of tunnel, the car slowed down and the traffic volume increased sharply. Others criticized that the auxiliary lane was 1 lane, which caused cars to overtake and affected the normal driving of the main lane. A series of problems lead to traffic jams, which will occur if it is not elevated all the way.