Hi
Another great response.
I have updated the code pen and its closer to what I want http://codepen.io/birdy247/pen/RajMdx
I am not worried about this mimicking a car race. I just want each marker to be independently controlled. If one is behind and then goes "over the top" of the other, that is fine.
My main worry was I could not adjust the speed of each marker in "real time".
From the code pen, it looks like this is possible? (Unless I am mistaken!).
I have built a timeline which takes the user through a series of transitions (they look like new pages to the user) before this "screen" is presented. So, should I simply omit this from the timeline and then when its time to play this sequence, just use some callback to trigger play()?
^^ Hope that makes sense