The over the road guys seem to keep it under 60... I see them on Highway 5 and 99% are right lane and under 60 mph...
It's the guys towing boats that seem to fly by... not all, but enough to take notice.
I tow every week at least once... sometimes 4 or 5 days and actually like going 55 in the slow lane... let all the fools in cars pass by 15 or 20 over the limit... and we do have a lot on 580 that drive without regard to the limit and 580 bans all trucks... which I think gives cars the idea it is lightly patrolled...