Quadruple Track Layouts
As it can be seen from the pictures below in the Gallery of diagrams, the four tracks can be paired either by direction (slow/fast in each pair) or by purpose (speed or direction in each pair).
Read more about this topic: Quadruple Track
Famous quotes containing the word track:
“Our achievements speak for themselves. What we have to keep track of are our failures, discouragements, and doubts. We tend to forget the past difficulties, the many false starts, and the painful groping. We see our past achievements as the end result of a clean forward thrust, and our present difficulties as signs of decline and decay.”
—Eric Hoffer (1902–1983)