Originally Posted by Canoe stream
What is the road-legal width for caravans in Europe?
The maxima are:-
Towing vehicle up to 3500kg GVW (7700 pounds), then
Length (excluding the coupling and drawbar) 7.0 m (22.9656 ft)
Width Maximum 2.3 m (7.54584 ft)
Towing vehicle over 3500kg GVW (7700 pounds), then
Length (excluding the coupling and drawbar) 12 m(min 4 wheels)(39.3696 ft )
Width Maximum 2.55 m (8.36604 ft)
Length of towing vehicle and trailer combined 18 m (59.0544 ft)
As there will be few tow vehicles in the UK with a GVW greater than 7700 pounds, a UK model Airstream would probably need to be maximum 7 ft 6 inches wide and less than 26 feet long, including the A-frame.
I hope this helps.