I took Cub Scouts in the local parade Sunday. Have done this a few times in the past few years(twice we wone 1st place!). I have towed with my Farmall-A, and my 16' flatbed trailer.
First, the tractor/float does not move unless all children are seated on the float. If they are not seated, the float stops, and they go march with the Cub Master. Th Placerville parade is about 3 miles; we stop and let the kids on the float switch out with the marchers. Again, we do not move unless they are seated.
The kids sit on hay bales. All hands/feet/arms/legs are inside the edge of the trailer.
All the trailers we have used when we have more than one flat, have fenders over the tires.
We have an adult walking near the front and back of the float on each side. The float does not move unless they give the all clear.
Although there are no brakes from the tractor to the trailer, I take the cable from the trailer break-away switch and add some strong string to it; I have it next to my shifter and throttle. If I have to panic stop, I can stop both the tractor and trailer quickly(The trailer will push the tractor in a panic stop; 1800lb 2wd tractor vs probably 3000lbs of trailer/hay bales/people/decorations)
We're very strict with safety. No issues in the 7 or 8 times we have done this.
Probably the hardest part, is me driving; the clutch on the Farmall wants to grab. Even though we only go about 1mph, if the clutch grabs it will lurch...
That said, we had a blast at the parade. Took about 20 kids this time around.
The marchers are out in front with the color gaurd. The tractor and float stays behind, with buffer room to emergency stop.