Assuming the track delimiting lines parallel, at every point (of one of the two lines) you have to find the perpendicular line and choose on it the point that is halfway the two lines of the track. :)
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke
