Beijing subway line 4 (updated)

OMG,I have never knew that it's too hard to build a subway...So it's a uncompleted version.
But it's much similar to the real one.
-----Controls-----
F/G:doors/driver's door
Sliders:left:engine right:break
up/down:same as my last car because I used my chip on it XD

PS.Don't forget to leave a like !
PPS.Never try to build a subway in Principia!!!