[bobeaston]

I'm ~mostly~ with the Toymeister on this one. The problem described by the OP seems unreal. Those sections of the MMP are wide open and there is plenty of room to pass. Maybe it was a timid cart driver, afraid to pass, that was more responsible for the backup than the trike riders?

My wife and I ride trikes on the MMPs and have found courtesy and compromise to be the best policy. When we are on MMPs, we ride single file and stay to the right. Typically, we are moving 8-10 mph, and carts rarely have problems passing us. Yes, occasionally they need patience to avoid oncoming traffic, but "backups" are non-existent in our experience.

On the split MMPs, and there's a long one through our village of Chitty Chatty, we often see carts approaching in our mirrors and move further to the right, dropping one wheel onto the turf to make room. Likewise, passing carts sometimes go by with driver side wheels on the turf. No big deal. Courtesy is reciprocal and very very rarely abused.

BTW, some split MMPs have curbing, such as some along Morse, that prevents the one wheel on the turf tactic. For those, we always check the mirrors to see the likelihood of being overtaken for those short splits. In that case, we pull over and wait, usually for only a few seconds.