I've seen dangerous driving/drivers in Roadster as far back as AMHA Nationals in the early '90s (OK City).I also loved to compete in Roadster; more than once I experienced scary driving by other competitors in the same ring. It's been a few years now; back then, I wouldn't say it was the majority...and IMPO, it was sometimes due to drivers who simply did not have a CLUE about proper ring etiquette. Didn't mean they weren't dangerous to themselves and others, though.
IMO, based on personal observation, I believe there is all too frequently a lack of knowledge of proper ring/driving etiquette within the Miniature horse breed ring...at least, the AMHA one(and such was also so in the only AMHR show I ever entered/attended, in CO sometime back.)It's not 'just' in Roadster; it's just more dangerous in a crowded, fast-moving Roadster ring.
For example...one should not be 'off the rail' except to (properly) pass, but two and three-deep is too often seen, sometimes to the extent that ring stewards/judges are literally in some danger of being run over. Yes, sometimes classes are too crowded, and splits not made when they should be, increasing the likelihood of this improper and potentially dangerous practice; time for thoughtful competitors to complain to management if this occurs.(Sadly, though, I fear that nowadays, more and more, such 'bad' driving is deliberate...all in the 'win-at-all-costs' atmosphere all too pervasive in these times.)
Breed rail classes, too,should be reversed on the diagonal,as notified by the announcer and directed by a competent ring steward, as Myrna described; safety is one paramount reason. When this is not done, and it is allowed to be just a sort of 'every man for himself(or woman for herself'! approach, I would again look to the management, and sugges that competitors(whose money it is, after all, that enables the show) step up to request changes to a proper approach. It just takes education.
Margo