Good info, thanks!

Now, this'll be the kind of thing that starts my "Engineer Brain" to start looking for solutions...

 

Some uhaul dollies have surge brakes but most don't in my experience. With how those things pivot while only stopping the front wheels I'm not sure I'd want brakes. I do know you always tell them you're pulling an insight, else they want to rent you the whole car trailer. I'd never want one myself but they are good in a pinch.

I've got a cop buddy was telling me a story of a mower that decided to stop in the middle of the road, no trailer lights. He got rear ended and the grasshopper ended up in the ditch on the side of the road, said it must have flown at least 30 feet. He didn't cite the guy for not having trailer lights or even unsecured load, just improper stopping.

I guess hope it's not a hipo guy and you'll probably be alright...