Not only did all Northern District equipment have to traverse Aliso Street, but such rolling stock as was stored at Macy Street during the day for other than Northern District trains had to deadhead through this vital link. In addition, freight motors bridging the gap between Butte Street Yard on the Southern District and/or Eighth Street Yard could only reach State Street via San Pedro and Aliso Streets.
Thus Aliso Street was usually a beehive of activity insofar as PE was concerned. No other single street offered a better display of so many different types of equipment, which in the course of almost any short period of time ran the gamut from city car to heavy interurban train, from box motor to electric locomotive.
Progress came early to Aliso Street in the shape of the multi-million dollar Union Passenger Terminal, opened by the three steam railroads (Southern Pacific, Union Pacific and Santa Fe) in May, 1939. This brought a heavy addition to the vehicular traffic using this thoroughfare and heightened the "Big Red Cars" battle for car space.
Next came the freeways. With Aliso picked as the connecting link between the Hollywood Freeway on the west and the Santa Ana-San Bernardino Freeway on the east. The first step was the construction of a huge new viaduct over the Los Angeles River and Mission Road. The original viaduct was built in 1903 and consisted of four lanes; center two lanes were PE private way, unpaved, while single lanes for autos were provided on either side. This was a grade level viaduct, making it mandatory for PE cars and autos to cross Santa Fe and Union Pacific steam tracks at grade at either end of the structure. The tragic 1915 collision between a backing Santa Fe steam switch engine and PE 422 killed several passengers and caused agitation of such magnitude that it led to construction of a high level bridge to cross both the river and the mainline rail trackage. The Aliso Street Viaduct was torn down in 1940 and replaced by the present freeway structure which entered service in mid 1943. PE participated in the cost of this mammoth structure, paying $350,000 as its share of the improvement. With the opening of the first segment of the San Bernardino Freeway (then called the Ramona Freeway) in August of 1943 a flood of autos and trucks descended upon Aliso Street. The Santa Ana Freeway added still further astronomical increases to the traffic flow in August of 1949. With each new freeway extension, more and more autos and trucks entered Los Angeles via Aliso Street, each further hampering PE's use of the street. One by one, interurban lines were abandoned and busses appeared in steadily increasing numbers. The final act occurred in July 1950, when the State of California notified PE that it was ready to rebuild Aliso Street itself to conform to the freeway design. PE could not (or so it claimed) pay the cost of relocating its tracks, so the stage was set for the disappearance of the "Big Red Cars" from the street whereon they had been seen for almost fifty years. On Sunday, September, 30, 1951 (the day after abandonment of the last two lines on the Northern District) PE cars ran along Aliso Street for the last time—Pasadena Short Line and Sierra Vista cars deadheading back to the city.
MAIN STREET: Prior to October 21, 1950 cars on the Pasadena Short Line and the Oak Knoll Line would enter the station concourse via Main Street. Cars leaving the concourse via Main Street were those on the Alhambra, Redondo-Gardena and Sierra Madre Lines. Watts-Sierra-Vista Line cars also passed on Main Street Pacific Electric's last cars to run on Main Street in regular service traversed the thoroughfare on October 21, 1950—the Watts-Sierra Vista Line. There followed a short period wherein a franchise car ran, but this ended on December 28, 1950. The official abandonment of PE trackage on East Ninth Street from San Pedro Street to Main Street, Main Street to Los Angeles Street, Los Angeles Street from 1st Street to Aliso Street, and Aliso Street from Los Angeles Street to San Pedro Street took place at 12:01 AM December 29, 1950.