This happened in 2006, but it must be added to the database of cases involving Driving Something Unusual While Intoxicated, for reasons that will be obvious. It's also a still-timely (and possibly timeless) holiday tale, of course.
In December of that year, this happened:
A man driving a float in the Anderson Christmas Parade … was arrested and charged with drunken driving after he pulled out of the parade and sped off at speeds reported as high as 60 miles an hour.
[The man was] charged with driving under the influence, as well as 18 counts of kidnapping and assault in connection with Sunday's incident.
I probably don't have to tell you that the kidnapping charges stemmed from the fact that, like many floats, the float in question was carrying passengers—in this case, a dance team.
[The man was driving] a Steppin' Out Dance Studio float … when authorities say he pulled out of the parade line near the Anderson County Courthouse on Main Street and passed a tractor pulling a float "at a high rate of speed for a parade," said Linda Dudley, spokeswoman for the Anderson [South Carolina] Police Department.
Dudley didn't say how fast parades normally travel in South Carolina, but based on my admittedly limited parade experience I'd think anything more than walking speed would be "high" in this context.
This raises a question I hadn't considered before but now seems very important: how fast would a parade have to be going before it would cease to be a "parade" and turn into a "high-speed chase"? Again based on my admittedly limited parade experience, they would be a lot more enjoyable if all the floats were going 100 miles per hour. I'd even watch the Macy's Thanksgiving parade if they could amp it up to 45 or so. Whether that would still be considered a "parade," I'm not sure.
In any event, this float did reportedly reach speeds of 55 or 60 mph "at points," which is a fairly high rate of speed even in a non-parade context. The driver allegedly ran two or three red lights during the incident and crossed a set of railroad tracks before finally stopping near a local community center, at which point the briefly kidnapped riders were able to disembark. The children were reportedly terrified, although looking back on it I bet they view flying along on a runaway Christmas float as one of the greatest experiences of their young lives. It'd be like getting in a knife fight with a clown: as long as nobody gets hurt, you'd never stop telling that story.
Whether or not it's a result of this event, the list of guidelines for the Anderson Christmas Parade now make clear that "alcoholic beverages are forbidden on any float, in any vehicle or on the person of any participant." They also state that "no participant shall use a live Santa" (presumably as an element of decoration) as the parade already includes one and "[c]hildren tend to be confused by anything other than the 'real' Santa."
The rules do not specify any particular speed limit.