Sleigh's are just inherently unstable & want to tip over if you are trying to follow the ruts of a tractor. Do _not_ put runners on the inside of your wheels, you need wide & stable, not narrow & tippy! A horse would either sense trouble & stop when you tipped, or panic & finish you off when you tipped - not leave you in-beween, ground up, like a tractor operator would..... /forums/images/graemlins/wink.gif I'd just not do the sleigh idea at all. They get caught in tractor tire ruts & pitch people out.
If there is any chance of unknown people riding with you some day, that flair box idea listed above is the _only_ way to go. A 2-wheel trailer likes to pitch around banging people up or pitching them out, and anything like a hayrack folks get the idea to hop on & off anywhere, turning an ankle now & then if not falling under the wheels. In this world, we always, always, have to think of liability. It's sad, but how it is under current law.
The flair box has 4 wheels so it is stable, the sides & front are high so no one wants to enter or leave on the danger sides - little tots will walk up to the back side where it is open not the front side where you don't see them & mow them down, and the back has a low floor so it is relatively safe for people to eneter & exit. With the 2 bench seats running fore & aft, people are looking across the wagon and are not as likely to drop something outside the wagon or drape body parts over the edge - getting caught or wrapped or pulled into something. The high sides hold people & kids in when they try to walk on a moving wagon & fall. The rear exit means if people fall out, they get bumps & brusies instead of a wagon tire on their rib cage. Medical costs for scrapes & brusies are high; lawsuits for broken bones & worse are out of this world.
Really would be the olny way to go if you were serious about hauling people around other than your very own children. Our laws are set up so you can mostly get away with maiming your own kids, while stupid people doing stupid things can sue you for all you own.
My view of it.
--->Paul