Just to set the record straight, the presence of air brakes has absolutely zero effect on whether or not a vehicle requires a CDL to be driven. None. Nada. Zilch. Zip.
As for the C7500, a quick search online shows various model years to have Gross Vehicle Weight Ratings from 31,000 to 33,000 lbs. - this exceeds the 26,000 lb. GVWR limit for a non-CDL license, so the answer would be yes... UNLESS, it falls under one of the following exemptions and circumstances pertaining to those exemptions:
The presence or absence of air brakes in a vehicle has no effect of whether or not it requires a CDL.
Air brakes have absolutely NO effect on whether a vehicle requires a CDL or not.
Air brakes aren't even a factor in determining whether or not a vehicle requires a CDL.
No
Air brakes have absolutely ZERO determination in whether or not a vehicle requires a CDL.
Yes
You don't need a CDL to operate a vehicle with air brakes if the vehicle doesn't fall within the requirements to mandate a CDL licenced driver to operate it. For example, RVs often have air brakes, as do many of the trucks manufactured for companies like FedEx, UPS, Merita Bread, etc.
The braking system doesn't determine whether or not a vehicle requires a CDL.
Air brakes have absolutely no determination on whether or not a vehicle requires a CDL. Zip. Zilch. Nada. Not just in Maryland, but in any state.
The presence or absence of air brakes has no impact on whether or not that vehicle requires a CDL.
No. Air brakes don't determine whether or not a CDL is required for a vehicle, and CDLs are for road vehicles - a trolley is a rail vehicle.
This will depend on: What use the bus is put to. Are you carrying passengers? Then yes CDL required What licence it has on it. Non commercial non passenger may not require CDL Air brakes. CDL required.