OK, I see my error. I had [the other day] seen tracks on Union St, which is parallel to Adelide and the next major street to the west. There are still tracks on Union St, visible here ...
[www.google.com]

So when I wrote my earlier post today, I conflagrated what I had earlier seen on Union St with the [residual ramp image] seen on Adelide St. I should have, today, followed Adelide St up to where I thought the tracks were before posting, and then written the post differently.

As an aside, I earlier lived in the Bay Area, although not in Oakland, and it is still surprising how much street trackage & odd shaped buildings indicating former presence of rails is still visible.