Ramona Bl-Garvey Av-Arroyo Av-Holt Av: This route is mostly upgraded to the San Bernardino Freeway. The first portion of this route, Ramona Blvd, seems to have been constructed in the 1930s, maybe late 20s. It was upgraded to the Ramona Freeway in the late 1940s. The oldest part is Garvey Avenue in Monterey Park. The western continuation was what is now known as Monterey Pass Road. The present connection to Ramona Blvd (now the San Bernardino Freeway) was built around 1930. Garvey Avenue ended at Valley Blvd in the old days. There is currently a Ramona Blvd connecting El Monte with Baldwin Park: this street was originally known as Holt Avenue. In Baldwin Park, this name continued on the street now known as Pacific Avenue to the San Bernardino Freeway. Holt Avenue then continued eastward toward Pomona. Some time, maybe originally or later, this was known as Arroyo Avenue.
A new connection between the Baldwin Park Holt Av (Arroyo Av) and the end of Garvey Av in El Monte was built in the early 1930's, I think. Over the Kellogg Hill, there was a connection, which is now partly Covina Hills Road, and partly gone. The connection into Pomona was built around 1930. This was all known as state highway 26, but signed as US99; later as US 60-70-99. As this was built as a state highway, when it was upgraded to freeway in the 1940s and 1950s, the existing alignment was used, rather than building a new parallel route.
Olympic Bl: Assembled from the widening and connecting of previously existing streets, Olympic was originally to be called 10th St, but was renamed Olympic Blvd in celebration of the 1932 Summer Olympiad held in Los Angeles. This was state highway 173, and posted (supposedly) as route 6 from 1934 to 1937, and as route 26 from 1937 to 1964 (to avoid duplication of US route 6, which was extended to California in 1937). In downtown Los Angeles, 10th St between San Julian and Lake streets was renamed Olympic. A curve was built to connect the street between Lake and Hoover streets. The street continued the route of 10th street between Hoover St and Crenshaw Blvd, with a straightening between Gramercy Place and Arlington Avenue, which left two short segments of the original 10th St. From Crenshaw to Lucerne Blvd a connection was built. The street continues on the route of Country Club Drive westward into Beverly Hills. A new roadway was built across the 20th Century-Fox lot, including a bridge with on- and off-ramps. Through West Los Angeles, Olympic basically follows the route of Louisiana Av: it took over Louisiana Av from Parnell Av to Granville Av. East of Parnell, it followed the line of Louisiana, leaving small segments of the original street. From Beverly Glen Blvd it seems to have taken over Lauriston Av, connecting with the Louisiana and Fox studio segments. In Santa Monica, Olympic took over the route of Pennsylvania Av between 20th St and its western terminus. Olympic was extended to the McClure tunnel. A new roadway was built to connect the West Los Angeles segment with the Santa Monica segment, running mainly on a curve just north of the Pacific Electric tracks.
The eastern and western segments of Olympic Blvd do not connect. The plan was to connect them by cutting a new segment from San Julian Street to meet 9th St somewhere around Stanford Av. This has never been completed. From Gladys Av eastward, 9th St was renamed Olympic Blvd. Through East Los Angeles, the street was originally called Mines Av or Mines St. It continues into Montebello, but ends at 4th St. Two small segments, unconnected to the main route exist in Pico Rivera, one between Whittier Blvd and Garrick Av, the other from Paramount Blvd [originally this segment of Paramount Blvd was called Lexington-Gallatin Rd] eastward. There is an "Olympic Wy", which was originally named Olympic Blvd, and the name Olympic Blvd continued eastward along the present Beverly Rd to the San Gabriel River channel.
Olympic Blvd was state highway 173 between Lincoln Blvd in Santa Monica and Telegraph Road in East Los Angeles. It bore the sign route number 6; later changed to 26, although the portions from Beverly Drive westward were not built before the number was changed to 26.
The Eastern portion of Olympic Blvd from Indiana St to Telegraph Road was signed as route 6, changed to 26. From some time in the 1940s until about 1955 it was also Bypass Route US 101.