Have you ever heard some caravanners argue this point: “Modern cars are more powerful and safer,” they argue. “Caravan chassis are better designed,” they may suggest. But despite all the arguments, you are still towing a huge weight mounted on just one 50mm towball.
On motorways, where there are potential hazards from side winds and disturbance from other passing high-sided vehicles, it is essential that you stick to the 60mph limit. These legal limits are set for your safety; if you should become the unfortunate victim of a serious ‘snake’ (a weaving instability where the trailer takes command of the car), you’ll have a far greater chance of exiting it safely than you would at higher illegal speeds. If you do get into a snake, don’t brake sharply; decelerate gradually, by lifting off with your right foot and keeping your hands loose on the steering wheel until the unit is tracking straight and true again. Remember the national speed limits for towing are there to keep all road users safe, so please keep to them.