Also, motorcycles are permitted to "split lanes" as long as you don't exceed 10 mph faster than the prevailing traffic. Now, I do not know if that pertains to motorcycles pulling trailers. However, even if you are not participating in that practice, it is something that you need to be aware of when you get caught up in some of that freeway chaos. Don't crowd the dotted lines, you may get a new streak down your side.
No splitting with a trailer!!!!! As posted, trailers are only allowed in the right two lanes. Lane splitting is between the left #1 and #2 lanes.
I lived and have towed trailers in CA at 70 mph, MC, utility, and campers, all the time and have not had any problems. It just depends on where you are and if the officer wants to give you a ticket or not. In high traffic areas on more than two lanes, I just stay in the right two lanes with the flow if traffic. Most of the time, that flow was at 65 mph. In the open areas where it is two lanes, I just run at 70 and do not worry about it much. I have had officers pass me when I was running 70 and keep on going.
In the high traffic areas, I can see the speed limit being lower with a trailer. But on the open two lane controlled roads, it is a joke and should be at least 65 mph. Here in UT on the interstates, we can run 80 mph with a trailer if you want!