You want to turn left. What driving line should you maintain?

When turning left on a narrow one-way street, you must keep to the right driving line. This ensures that you do not cut into the lane of oncoming left-turners from the opposite direction and lets other vehicles pass on your left if the road is wide enough. It is a standard rule in Germany to take the right lane or driving line when turning left from a one-way street, unless otherwise marked. This improves safety and traffic flow, especially in areas with limited space. Your answer is correct for this situation.