Originally Posted by MuttJockey
In most states, if you are towing more than 1500 lbs., the vehicle being towed (either a dolly with a vehicle, a flat-towed vehicle, or a trailer with a vehicle) has to have brakes.
By way of example, a JK Wrangler comes in at almost 4000 lbs. with a full tank of gas.
Not that I would ever advocate towing a Jeep without brakes, but there's a little mis-information here. It's a common misconception that a vehicle in tow is required to have brakes in most states. In reality, the vehicle code in many states consider trailers and vehicles in tow as two different classes, and they have different rules.
This mistake is perpetuated by many of the brake manufacturers because the trailer rules are much more strict. For example, in CA, any trailer over 1500 lbs., but a vehicle being flat towed doesn't have that requirement. Instead, vehicles being flat-towed are required to meet a braking performance standard (stopping in x feet from y MPH). The reason for this is that towing a 5,000 lb Jeep behind a 6,000 lb pickup is very different than towing the same Jeep behind a 35,000 lb bus.
A number of states have adopted a similar performance standard for vehicles in tow. And then there are other states that make a distinction between a trailer and a vehicle in tow, but only specify regulations for trailers.
Just trying to spread some info that is more complete.