I thought that this underpass picture looked familiar, but I can't see any previous postings. Maybe it just looks like other underpasses built around the same time. The crossing was previously at grade.
Photograph article dated September 7, 1948 partially reads, "State engineers working on the Valley's $2,000,000 continuation of the Hollywood freeway turned to paving work today after opening the Lankershim boulevard underpass in time for Labor Day traffic....Opening of the underpass marks the first time automobiles have passed over a part of the Hollywood freeway extension which will eventually provide a highspeed route from Cahuenga pass to Valley points. Pacific Electric trains have been crossing over the grade separation bridge for weeks, while workmen paved lanes of Lankershim boulevard into Cahuenga boulevard. Eventually the freeway traffic heading to and from the Valley will pass over the heads of motorist on Lankershim boulevard on divided lanes bordering the P. E. tracks."
LAPL
The original design was still in place until at least 2011...
GSV
...but 2014 saw the parapet being rebuilt.
GSV
By the end of 2014 we were left with the current, filled-in design.
GSV
I originally assumed that the parapet had just been made blander for no reason, but then I saw that the wall on the northern side was being held together with sections of barrier for years before the works in 2014 (see below - by 2014, the lane was even closed off with K-rail). With that said, I still wish they'd repaired the damage with the original design (or at least retained elements of it).
GSV