There must be a dozen studies on reopening the SDA&E I've seen over the last 20 years. All of these studies indicating significant costs to reopen and sustain operations. These costs depended on the quality of "restoration" and desired operating parameters (speed, clearances, capacity, controls, redundancy, maintainability, etc.. These studies were done for a variety of potential traffic scenarios mostly dependent upon on issues affecting various port traffic assumptions and the need for direct connectivity to the UP (via El Centro, as opposed to via IC at Colton from the existing LOSSAN/BNSF rail freight connection).

I've seen estimates to restore the SDAE as a connection ranging from $30 million (very optimistic and very bare bones) to nearly a billion (container stack/full clearance/higher speed) for the modern "blow out" freight RR. It is in rough country and some poor geology with significant engineering and/or costly maintenance requirements for either restoration or upgrading.

Most of the more optimistic traffic scenarios making San Diego a significant Pacific Coast rail served "port" seemed very unlikely given the dominance and better rail access of LA-LB for containers. And, for San Diego today there is the cheaper existing connections, which could serve the UP at West Colton via the LOSSAN (for existing bulk ag or auto racks which are the most likely traffic opportunities).

So much as I love this line, its economic potential to support the necessary levels of investment for even minimum restoration or the necessary levels maintenance to sustain operations would seem to be very low, at least without some kind of a "game changing" event to change the existing "most likely" assumptions.