[4] The line will initially use 36 sets of six car B-type trains with a maximum service speed of 80 km/h (50 mph).

Then it turns south into the North Outer Ring Expressway where it turns east-west running under the elevated expressway forming a three level structure similar to the northern section of Shanghai Metro Line 1.

[3] After reaching Jiangbei Avenue, it starts to turn underground and deviates from the viaduct to Zhuangqiao Railway Station where it turns south, crosses Yaojiang River and reaches Ningbo Railway Station.

[1] The Phase 3 of Ningbo Rail Transit includes both western and eastern extensions of line 4.

[7][8] Eastern extension started construction in 25 February 2021,[9] and western in 22 November 2022.