CDL study guides
Concise study notes for every CDL endorsement, written against the public-domain FMCSA CDL Manual. Read these before you drill the practice tests — the question banks reward understanding, not memorization.
GK
General Knowledge
Required for every CDL applicant.
ABAir Brakes
Required to operate any vehicle with air brakes.
CVCombination Vehicles
Required for Class A combination drivers.
HHazardous Materials (H)
Required to haul placarded hazardous loads.
NTanker (N)
Required to haul liquid or gas in bulk tanks.
TDoubles / Triples (T)
Required to pull more than one trailer.
PPassenger (P)
Required to drive a vehicle designed for 16+ riders.
SSchool Bus (S)
Required to drive a school bus.