Although I would never do this, I was wondering if someone who is legally over the limit is riding as a passenger on a motorcycle is it considering drunk riding? I only ask because a passenger who is not cooperative could have a substantial influence on how the motorcycle handles.
How about if you are drunk riding a bicycle, roller blading or a skateboard?
You would have to look at specific circumstances and the specific laws in every state to be sure but it is a good bet that it would be somewhere. “Driving” isn’t always the key part of DUI laws. Being in control or having control of the vehicle is. It is perfectly possible to have never driven motor vehicle in your entire life and to still get a DUI. All it takes it to sit in the driver’s seat with keys in your possession for a charge. Many people who have opted to sleep things off in their car have been hauled in and convicted for that no matter how long they planned to sit there. You can also get charged for a DUI for riding a lawnmower over the limit or a bicycle. I don’t know of any tandem bikes where you don’t have some control. The possibility is there which is a good thing because passengers do have some control over the vehicle.
I can’t say if anyone has ever been convicted of this but it could happen given the right state and circumstances.
In Ohio it was called “Interferring with the Operation of a Motor Vehicle”. At least in 1980 it was when a drunken college roommate grabbed the shift lever on my Camaro and jammed it into reverse because he wanted to get out closer to the dorm; thus sending us over the curb and into a parked car at 40 mph (200 feet from where we were going to park anyway!). :mad:
I never get cited for breaking his nose ten seconds later; it happened in the accident officer; really truely did!. 
PA, late 80s, on a motorcycle – my passenger was acting fairly stupid, moving a lot, and finally tossed his cookies down and to the right - and all over the Statie following us. His ticket was for “public intoxication” and I got a cite (along the lines of a mechanical) short of a ticket for “questionable operation”. I was stock cold sober but the argument was that by moving with a passenger in such a condition I presented a hazard; the cop was probably right.
I’ve ridden drunks before and since but usually quiet sleepy drunks. Cops don’t seem to mind those. Some I had to bungiecord to the sissiebar.
ROFLMAO… Dammit, man! I nearly fell out of my chair, I laughed so hard! I know that there’ve been more than a few times, that I wished I HAD a sissie bar, to strap someone TO! 
Did bunglecording them to the sissiebar keep them from leaning when you, the driver, would lean?
On the one scoot in particular, yeah. It was one of those old school 4 foot jobs with the iron cross on the top. Seriously rigid bar stock. Not only did it hold the average drunk, I once tied off a 7 foot Christmas tree to it and made it the 10 miles home.
Riding with an object fixed and upright isn’t easy but it beats having an object lean with you ------ and then keep on leaning to the point of falling off. Had that happen once or twice too. :smack:
Buy me a beer some day and I’ll teach you how to carry 20 cases of beer - one trip - using a Sportster. Another “old fart” trick.