US 66 1935 alignment via Eagle Rock + pre-1936 via Royal Oaks Ave in Monrovia?

[sparker]

An interesting side-note about the Arroyo Seco/Pasadena Freeway signage -- at least prior to the incursion of the I-5/Golden State freeway in 1961-62 -- was how the left exit (NB currently but EB re former US 66) for North Figueroa and Avenue 26 was signed.   During the "heyday" of the '50's, after completion of the downtown section of the then-Pasadena Freeway (the part bypassing Chinatown between the Spring St. exit and the 4-level interchange), that facility had four route numbers using it:  US 66, US 99, US 6, and SSR 11.  All but US 66 exited the freeway at that left exit, which also peeled off the freeway's left lane.  Overhead signage (white on black during that period) was specific -- except for the decided lack of control cities for that exit.  The thru right lanes were labeled "EAST US 66, PASADENA FREEWAY, PASADENA" -- initially all in text; no shields.  The same applied to the left exit lane -- "US 99, US 6" (but w/o cardinal directions), Alternate US 66".  SSR 11 didn't get a mention on the overhead signage, but there were a couple of trailblazer reassurance assemblies positioned on the left side of the EB carriageway with 45-degree LH arrows indicating the four routes to be accessed with the exit, including SSR 11.  But prominent on at least two of the advance "BBS's" approaching the exit was signage stating "NO TRUCKS OVER 6000 LB. ON PASADENA FREEWAY".  The exit wasn't specifically labeled as a truck route, but that was implied; the idea was to divert any through truck traffic onto the old (LRN 165) alignment up Figueroa, continuing the practice initiated back in 1935.  I do remember as a kid driving over Colorado St. into Pasadena (my mom shopped there often) and seeing quite a few trucks coming off Figueroa -- a sign the "default" truck route was at least functioning.  And, IIRC, at the intersection of Colorado St. and Arroyo Ave (the surface extension of the Arroyo Seco Parkway/Pasadena Freeway), there was clear signage stating the truck restriction -- as well as the "Alternate US 66" junction -- which effectively extended the implied truck route to the opposite direction.   The fact that until the alignments diverged north of York Blvd. US 66 and Alternate US 66 were only a few blocks apart tends to indicate that the whole "Alternate" purpose was to supply such a route for traffic deemed inappropriate for the narrow and curving parkway lanes. 

BTW, trucks were permitted on the segment of the Pasadena Freeway hosting the 4 signed routes until the Golden State/I-5 freeway interchange was fully opened at the end of 1962;  the Harbor Freeway/Santa Monica freeway interchange opened within weeks of the former.   At that time the truck restriction was extended south through the tunnels to the 4-level interchange; 20+ years of trucks attempting to shift to the left lane inside the tunnels in order to make the left exit -- and the various incidents that occurred as a result -- was more than enough for D7!   Advance signage of that was placed on the Harbor Freeway all the way down to the Santa Monica/I-10 freeway interchange; the intent was to place all through commercial traffic intended for NB I-5 on EB I-10 around the downtown area so as to pass through the ELA interchange rather than the 4-level -- although truck traffic heading toward north US 101 still stayed on the Harbor north to the 4-level, as it does today.   

Also remember that in respect to freeway signage, at the time that signage was being placed the Division of Highways was at the beginning of their "learning curve" about such things; future truck detours, such as that using I-238 and I-880 as a truck route along the similarly restricted section of I-580 in Oakland, are much more clearly indicated these days.