The rules in Europe are pretty different.
- Under 750 kg trailer GW, nothing is required, only a $10 license plate with a copy of the tow vehicles registration.
- Over 750 kg trailer GW, it needs to be registered, has its own VIN, and gets it own license plate. (this was done to put a stop to the massive amount of trailer theft.)
- Car + trailer gross weight over 3500 kg = a trailer towing license is required, so a special trailer driving exam.
- cars cannot weight over 3500kg gross weight, or they're classified as trucks, requiringa truck license
- trailers cannot have a combined axle load of more than 3500 kg, anything over, requires it to offload on the towing vehicle with a 5th wheel. (These exist, as a cheap alternative to a fullsize truck. Usually for moving construction equipment)
-cars have a braked and unbraked towing weight registered on the papers. The braked towing weight is usually around the cars empty mass, the unbraked is usually half of the braked mass.
-you can (as of this year) tow a large, but empty trailer behind a smaller car, as long as the weight in reality doesn't exceed the cars tow rating.
-and for ecomodder: most hybrid and electric cars, and some of the "low emissions" cars, have 0 towing weight registered. So no trailer behind a Prius or a Tesla.
This is me, moving house with a large trailer behind my small econobox:
That went pretty well, even though it doubled my fuel consumption for that trip.
Sadly, my government has decided diesel cars older than 8 years are evil, and starting 2015, the first city will ban them, and a lot of other cities will have to actively choose not to ban them, or will also ban them. I'm currently saving money for, and looking at new cars, I'm thinking hybrid, for good fuel economy without diesel. (And add a plug-in pack, because I always wanted an EV, and DIY conversion of a normal car is not legal or very expensive).. That would mean no more trailer towing for me, unless I borrow or rent a different car..
Other than that, our tax system heavily taxes purchase and ownership of a vehicle, with a monthly tax based on vehicle weight (and multiplied by 3 for diesels), mandatory insurance, and 200% tax on fuel, and a huge tax on import or new cars. Owning a heavy vehicle is not a good idea, unless you really need it very often. Thats why almost everyone drives "normal" and compact cars, and uses trailers for moving big stuff.
The number of pickups I see around town is extremely low, I literally see more Tesla model S' than pickups. Vans are popular though, almost everyone who works in construction buys or leases a van, and turns it into a mobile tool shed.