From the countless threads on GMR it doesn't appear as though there is much traffic regardless. I assume no one commutes on GMR Any preference as to weekend or weekday? I've driven to SoCal many times so I understand the traffic situation; any sort of early start should produce a finish in time to drive back up north that afternoon.
I have four climbs on my bucket list: Mt. Hamilton, Mt. Tam, Mt. Diablo and GMR; I'm determined to get them done in 2014. I figure if I do venture down to do the much-publicized GMR I'll have legitimized my posting in the SoCal sub-forum.