This has been there for as long as I can remember, at Trabuco and Modesto in Mission Viejo. I wonder how it got there:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi96.photobucket.com%2Falbums%2Fl200%2Fmrkf%2Fold-405-postmile-MV1_zpsemon43xu.jpg&hash=1aa10574416f11e33ea4a6fb0adaefe02e29e3da)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi96.photobucket.com%2Falbums%2Fl200%2Fmrkf%2Fold-405-postmile-MV2_zps0vqbco9l.jpg&hash=bc04f194559aae0fe95b6db4fd38800e0a248b07)
A postmile sign for mile 18 of 405 in LA county, which would be around the Inglewood Ave exit in Lawndale. Can't tell what it is marking now.
I grew up right across the street from here and have always wondered why/how that got there. Would live to hear anyone's insight about this phantom postmile.
Was it part of a temporary routing prior to the completion of the San Diego Freeway? Or was that a post meant for another highway and it got mixed up?
No, the sign is not official in any way other than when it was originally posted on Route 405 in Los Angeles County. It is most likely a "prank" of some sort that was done long ago. Since it looks "official", maintenance crews most likely have left it alone since then.