Guys.. When I was ticketed a few years ago, here was one of the key things to keep in mind.

"Any tandem axle trailer can carry at least 5000lbs and is therefore considered over the 4500gvw and subject to the laws above which definitely require trailer brakes, a breakaway device and yearly inspections."

You may get away with a trailer registered under the 4500 limit most times, but a difficult cop can still ticket you without the break away device.