See the report in the previous thread for an understanding of the assumptions.
SBCAG/SCAG LOSSAN North Study
If it is not in here, then google LOSSAN North Study-There will be more.... It may have been Cambridge Systematics or someone else who did the presentation on needs, back then....
IIRC, the UP wanted many slots, hence the rationale behind some of these current siding extensions, it was something like capscity for a minimum of 12 daily through freights.... That was back when there was still about 3 or 4 times the Coast carload volumes (oil, ag, etc.) and some through freight still using the Coast, albeit infrequently, before the miracle of "PSR"....
When it takes you 13 years just to get the funding and finally start construction, things can change a lot.....