... fall into that trap again. All the best, Brian Nicholls. posted: 26 May 2011 21:21 from: Martin Wynne Brian Nicholls wrote: Now you say, there are only two intersections, in reality, there is only one true intersection where the centre lines of the two tracks cross each other, since the two roads diverge away from each other, in either direction, to infinity No Brian, if two circles intersect at all, there will always be two real intersections (A and B here): 2_261617_120000000.png It's possible for both intersections to be coincident if the curves are tangential, but there will always be two intersections or none. I think maybe it was a mistake for me release the TDV before I had written the help notes containing diagrams such as this. I really did think this stuff would be obvious to everyone. regards, Martin. posted: posted: 26 May 2011 21:35 from: Paul Boyd HI Martin I think maybe it was a mistake for me release the TDV before I had written the help ...