Opened on 30 March 2011,[1] the line is a rapid transit (metro) system consisting of 14 stations - 8 underground, 1 on-ground, and 5 above-ground.

Unlike lines 1 to 3 of Busan Metro, the trains are driverless and run with pneumatic tires on concrete track (Roll way) between two guide bars.

Their main body is white and circled by a blue frame and the station name is printed in big Hangul near the top with smaller English and Hanja names near the bottom, with the English name having the station number beside it.

There are many reasons for this; however the most significant one is that there were many artifacts found in the construction site of the line, including those from the time of the Three Kingdoms of Korea and the Joseon Dynasty.

Woojin Industrial System Company Limited, supplied urban rubber tire trains for Line 4.