Back in the late 1970s, San Diego had several freight trains per "day". Most nights saw the SDX out of Barstow, power could be anything from GP30/GP35 up to newest 4 or 6 axles. The Night Coast out of Hobart (LA) usually had 4-6 GP30/GP35, was moving primarily the interchange traffic from SP (and UP?) including copper concentrate out of Arizona that was supposed to go over the SDAE if it was open. Both trains had a pretty decent cut of pigs on the rear for the ramps in San Diego. There was a 4th district local that went on duty in the evening, worked Miramar and came to Oceanside a few nights. Rotated Escondido local power to San Diego for servicing over the weekends. Would also work as far as San Juan Capistrano - there were a couple packing houses and last one was a station (name?) where the tracks turned in from the coast to SJC that used to ship carrots. The Escondido was running heavy mostly with chicken feed and silica sand weekdays, switched Oceanside on Saturdays. Some extra potash(?) trains exported out of San Diego.

Much of this traffic is now gone. A new TOFC facility was supposed to be built at Miramar but never appeared. During the 80s the Escondido local ran MWF to its namesake, Miramar the other days - all now run at night by Pacific Sun but far fewer customers. Still some lumber, steel and vehicles into San Diego by the old SDX, but not near what it used to. Plus whatever is going to SDIY or TJ. There just isn't any real demand for freight rail in San Diego.

There was a master plan to extend the San Diego Trolley up the median of I-15, and when US395 was rebuilt into I-15 it did have a wide center median to allow this. For some reason the whole idea was dropped, and since then it has had several very expensive rebuildings first to add a directional carpool lane in the median with more travel lanes, and then again to add carpool lanes in both directions and even more lanes. The trolley extension would have easily been paid for, and would have connected San Diego and the Sprinter to the rest of the San Diego transit system. The freeway is still a parking lot.

Rebuilding the old Cal Southern from Perris to Oceanside would be interesting. The corridor from Fallbrok/Temecula/Murrieta/Perris has ended up being a bedroom community with tons of commuters in each direction. No chance of following I-15 to Escondido and on to San Diego, but I can see where there would be plenty of commuter demand, not so much long travel. No doubt the BNSF SANBAR/BARSAN(?) would take it as a shortcut. It would take the cooperation of the feds to get through Camp Pendleton again, but I doubt it will ever happen because of real estate costs and way too many NIMBYs who would rather park on the freeway.