In Europe you can tarvel under convoy eceptionalle, or as they are better known in the UK as STGO (Special Types Goods Orders, and covers width length and wieght, but the load has to be indivisable to qualify. Eg a beachcat with beams wouldn't qualify as it can be taken apart, but a yacht of 10 ft beam would. It then means markers have to be diplayed and if i remeber correctly once it goes over 1ft overhang either side then an escort is required