mark surface based on curve occupancy

Hi, 

I need to move some curves along some trajectories, but they should not intersect. So once they collide they should stop. For this, I am thinking that the parts of the surface on which the curves are moving could be marked ( something like occupied or given a color ) if any of the curves occupies that area, and any other curve can check ( the entire solution should be VB code ) whether the area it will move to next is occupied or not.

Does anyone know which would be the best component to use as a surface 

on which the curves are to move ? I would need to be able to mark it at Point level.

Thanks