I drove in the "Great Eastern Iowa Tractorcade" a couple weeks ago. There was a total of 530 tractors. This annual 3-day ride is organized the past 12-13 yrs by WMT, a radio station in Cedar Rapids, IA. Drivers come from as far away as CA and VA, and many from MN, IL, and WI. They announce the dates and route in January; a friend of mine in IA immediately calls me with that info and I immediately line up motel rooms. You then google "WMT Tractorcade" for the entry forms, rules, etc. Then you get your entry sent in pronto as those Iowans are avid riders in this event and they have a limit to entries.
They set up 7 "speed groups"; slowest go first in morning then following groups follow with faster speeds. Speed is not a contest, it is what you want to cruise at. I get in 3rd group, at 13 mph, and my H Farmall is at low throttle so I can see the scenery and relax. There is a group leader and tail end driver. Police, deputies and IA hwy patrol are everywhere and they wave us thru stop signs and red lights...rarely every stop while driving. Rules are strict; no passing, no hot rodding, no stopping except for breakdowns, etc.
Lunches are served at rural churches, noon meals at large high schools. I think we averaged 100 calories per mile this yr.
LA in WI