The trailer is chosen by height first and weight second. A standard flatbed deck sits about 1.5 m off the ground, which leaves roughly 2.6 m for the load before most routes hit their height limit. A step deck drops the main deck to about 1 m, buying another half metre. A double drop or removable gooseneck lowers it further again, to around 0.6 m, which is what lets a large excavator or dozer travel without a height permit.
Weight decides the axle count. A legal five-axle combination carries a modest load; heavier machines need extra axles, which in Ontario and several other provinces allow far higher gross weights than the US federal 80,000 lb limit. That difference matters on cross-border moves, where a load that is legal in Ontario can be overweight the moment it reaches the US side.
The RGN is the answer when the machine has to drive on. The front of the trailer detaches, the deck lowers to the ground and the machine climbs on under its own power. If the unit cannot drive, because it is new and unfuelled, damaged, or an attachment rather than a machine, loading needs a forklift, crane or ramps, and the site has to have one.
The cheapest move is almost always the one that avoids permits. Removing a bucket, a counterweight or a cab guard can bring a load back inside legal dimensions. We ask the question at quote time, because it is often the difference between a one-day move and a three-day permitted one.