I will add what I copied from the Q&A at the FMCSA (Federal Motor Carrier Safety Admin.) web site below.
The law says that if you have a GCWR of more than 26,000lbs when the trailer is over 10,000lbs GVWR you must have a CDL. The important wording here is "more than 26,000lbs". What that means is, if for example you have a truck with a GVWR of 12,000lbs and a trailer with a GVWR of 15,000lbs, then you have a gross combination weight rating of 27,000lbs and you would therefore need a CDL because you are over 26,000lbs GCWR. But if you have a truck with a GVWR of 10,000lbs and a trailer with a GVWR of 15,000lbs, your GCWR would be 25,000lbs and therefore you would NOT need a CDL because your GCWR is under 26,000lbs. Also, if you had a truck with a GVWR of 20,000lbs and a trailer with a GVWR of 8,000lbs, you have a GCWR of 28,000lbs, but you do not need a CDL even though the GCWR is over 26,000lbs because the trailer is under 10,000GVWR. If the trailer went over 10,000lbs GVWR giving you a GCWR of over 30,000lbs, you would then be required to have a CDL.
The following has been cut and pasted directly from the FMCSA web site at :
http://www.fmcsa.dot.gov/rulesregs/fmcsr/regs/interp383.91.htm
Question 2: Is a driver of a combination vehicle with a GCWR of less than 26,001 pounds required to obtain a CDL even if the trailer GVWR is more than 10,000 pounds?
Guidance: No, because the GCWR is less than 26,001 pounds. The driver would need a CDL if the vehicle is transporting HM(hazardous materials) requiring the vehicle to be placarded or if it is designed to transport 16 or more persons.
Question 3: Can a State which expands the vehicle group descriptions in section 383.91 enforce those expansions on out-of-State CMV (commercial motor vehicle) drivers by requiring them to have a CDL?
Guidance: No. They must recognize out-of-State licenses that have been validly issued in accordance with the Federal standards and operative licensing compacts.
In my earlier posting titled "First Load...Trial by Fire" you can see my hotshot rig that is rated at 26,000lbs GCW (Gross Combination Weight). My Truck is stamped 10,000lbs GVWR and the trailer is stamped 15,000lbs GVWR. I do not have a CDL and it is not required that I have one. I've been stopped at several scales, and after giving them my standard class "D" driver's license, I have never had a problem.
With regard to the eye, I believe your friend will need to get a Skills Performance Evaluation (SPE) Cetificate before he can get his medical card or a CDL. He needs to call his regional DOT office and talk to them about what is required in order to receive a medical waiver.
I hope this helps to resolve any questions.
