Nittany Valley Running Club

A simple rule of thumb for staggered starts on a track is that each solid-line-stagger after the start represents the stagger for one turn. So whichever lane you are in, if you want to run 200 meters, start at the first solid-line stagger in that lane. If you want to run 400 meters, start at the second solid-line stagger, etc.

For an excellent and more complete explanation of track markings, see Runner's World.