You may need to check with DOT but I would think it's going to fall in the category of other commercial vehicles of the same size.
I know of some guys that used them years ago for off road wreckers and things like that. They sit really high to put a very tall dump bed on and really pretty high for flat bed use. I also remember someone having one with a water tank on it to wet dry ground for compaction during the dry season.
Basically there may be very specific applications where one would be great, if needed to go off the road and work on rough ground when it reaches the job site, etc, but if your going to be on the black top and just off in the dirt making a delivery your better off with another tandem truck with the right suspension, motor and gearing.