Bill Bradley's book about LAUPT, "The Last of the Great Stations", has a photograph (page 58) of the San Francisco-Los Angeles "Lark" running down the middle of Alameda Street on its way into Central Station.

The accompanying caption makes the case that the traffic congestion generated by the SP in-street operations was one of the main reasons why the city wanted to grade-separate incoming passenger routes and build a true "union" station.

Apparently, had SP gotten its way, it would have elevated its passenger tracks into downtown L.A. and continued to use Central Station. The trackage would also have included Pacific Electric lines into and out of downtown. An artist's impression on page 60 shows the planned elevated structures.