@Hal Leopern I 100% completed it,it's possible. Notes in the description have been written.
You just let the locomotives move to the other side,make sure they have been properly connected.Then check the train's Shunting Quene,if there is anything inside,delete them. Then the train will run at the greatest speed.
For specific tutorials, please refer to https://www.bilibili.com/video/BV14g4y167ES

Train K5447 is late no matter what

Can you make the trains that have to switch locomotives have locomotives on both sides so the map can be 100% completed? Or at least add shunting signals?