Site Visibility Tool

I am using the sight visibility tool to calculate the line of sight along my alignment.  

Not used it before as not something that was needed in my previous heavy  rail exp, but now I am designing Tram alignments it plays a crucial role.

Generally Line of sight is calculated on the basis of speed, cant using whatever constant values are applicable for accel/deceleration (i.e. 1mpss)and non comp acc' (i.e. 0.65) using the formula in attached spreadsheet which gives you the visibility distance for curve/cant speed combination. Fine!  

Trouble is that the software only seems to take the values as a catchall for all alignments because say if I set a chainage range to show LOS for a particular curve and then I wish to change values for a different curve and apply, the software erases the LOS data produced for the previous curve(s). Worse still it appears that it is erasing the data for one alignment when applying the tool to the corresponding track 2 alignment of a dual track? Not good.  

I have looked at how BRT is creating the MS elements in an attempt to drop, regroup or copy them but there is still a linkage that erases the new copied elements when applying the tool again.  

What is the recommended process and How do other users use / manage the tool whilst carrying out LOS analysis.   I need to get feedback on this quite urgently if poss' as I am producing a set of LOS drawings.  

Regards

Chris Murray

Linesight Driver.xls