Many thanks Keith. I think I am starting to understand that nuance.
So just to clarify, if I am asked to calculate the TOD then it's the graphical distance and surface and condition factors.
If I am asked to calculate the TODR then it's the graphical distance with surface/condition factors AND the REGULATORY factor.
And if this is a question of TODR, then the regulatory factor is 1.15 for unbalanced field, and 1.25 for balanced (no stopway/ clearway)
If it is a question of ASDR, then the regulatory factor is 1.3
Am I getting it right?
Thanks