OmegaMan, when you think about it, a 40 foot motorhome is a 40 foot motorhome for the purposes of driving it whether it has that rack on the back or not. So nothing changes as far as driving is concerned so no change in license required. But when the restriction is for the curves and narrow road, than that extra 4 feet in the back may make a difference assuming it's also as wide as the motorhome. So I can see why the length rules would be different. This particular length limit deals only with the size of a one vehicle unit. So you can be 40' and have a toad as long as you don't exceed 65' and still drive on Highway 108. But if your motorhome is 41' even with no toad, then you aren't supposed to drive on the road.