The one comment I would make about these convoys is that if they get large it can be difficult to stick together. What happens is that the cars at the end of the pack have to drive a lot faster to catch back up and tighten up the convoy. It is helpful for the leader to set the speed at the speed limit until the group gets back together on the freeway so the people at the end don't have to drive ridiculously over the speed limit to catch up (and even then if the leader keeps it only a few mph over it is easier for the group to stick together). This was a problem last year. Not trying to be a granny driver, I just want to keep this thing safe.
Just my 2 cents,