CDL (Commercial Driver's License)
A license required to operate commercial motor vehicles in the United States, classified as Class A (combination vehicles over 26,001 lbs), Class B (single vehicles over 26,001 lbs), or Class C (hazmat/passenger). CarrierOk reports total CDL drivers per carrier as a fleet composition signal.
Learn moreWhat is CDL?
A Commercial Driver's License (CDL) is required by federal law for any driver operating a commercial motor vehicle (CMV) that meets specific weight, passenger, or hazmat thresholds. CDLs are issued by individual states but governed by federal standards under 49 CFR Part 383. There are three classes: Class A permits operation of combination vehicles (tractor-trailers) with a gross combination weight rating (GCWR) over 26,001 lbs where the towed unit exceeds 10,000 lbs; Class B covers single vehicles over 26,001 lbs GVWR (straight trucks, buses); and Class C covers vehicles that don't meet Class A or B thresholds but carry hazardous materials or 16+ passengers. Endorsements extend the CDL for specific operations — H for hazmat, N for tanker, T for doubles/triples, P for passenger, and S for school bus. CDL holders are subject to stricter DUI standards (BAC 0.04% vs. 0.08%), mandatory drug and alcohol testing, and medical certification requirements. CarrierOk reports the total number of CDL-holding drivers per carrier (total_drivers_cdl), which is a useful fleet composition metric when compared against total power units to assess driver-to-truck ratios.
Why does cdl matter?
Insurance Underwriters
The CDL driver count relative to power units indicates whether a carrier runs owner-operators (low ratio) or company drivers (1:1 or higher) — different risk profiles and policy structures.
Freight Brokers
A carrier with endorsements matching your commodity requirements (H for hazmat, N for tanker) is operationally qualified — checking this upfront avoids load rejections at pickup.
Developers & Platforms
Use total_drivers_cdl alongside total_power_units and total_drivers to compute driver ratios that feed fleet classification models — a carrier with 50 power units and 3 CDL drivers is almost certainly a leasing operation.
Key values & thresholds
| Category | Value |
|---|---|
| Class A | Combination vehicles > 26,001 lbs GCWR |
| Class B | Single vehicles > 26,001 lbs GVWR |
| Class C | Hazmat or 16+ passengers |
| DUI Threshold | 0.04% BAC (vs. 0.08% standard) |
CDL in the CarrierOk API
This data is available via the /v2/profile endpoint. The following fields are returned in the carrier profile:
/v2/profiletotal_drivers_cdltotal_driverstotal_power_unitsFrequently asked questions
What are the CDL classes and what can you drive with each?
Class A covers combination vehicles (tractor-trailers) with a GCWR over 26,001 lbs where the towed unit exceeds 10,000 lbs. Class B covers single vehicles over 26,001 lbs GVWR like straight trucks and buses. Class C covers smaller vehicles carrying hazmat or 16+ passengers. A Class A license holder can also drive Class B and C vehicles.
What endorsements are available for a CDL?
Key CDL endorsements include H (hazardous materials, requires TSA background check), N (tanker vehicles), T (doubles/triples), P (passenger vehicles), and S (school buses). Each endorsement requires passing an additional knowledge test, and the H endorsement also requires a skills test. Endorsements are noted on the physical CDL and in state DMV records.
How many CDL drivers does a typical trucking company have?
It varies enormously by fleet type. A single owner-operator has 1 CDL driver. Mid-size carriers typically have a 1:1 ratio of CDL drivers to power units. Large truckload carriers may have 1.1-1.3 drivers per truck to account for team driving and driver turnover. CarrierOk reports total_drivers_cdl per carrier so you can calculate this ratio yourself.
Related terms
ELD (Electronic Logging Device)
A device installed in commercial motor vehicles that automatically records driving time and hours of service. ELDs replaced paper logbooks and are mandated by FMCSA for most interstate carriers since December 2019. HOS violations captured by ELDs feed directly into a carrier's BASIC percentile scores tracked by CarrierOk.
HOS (Hours of Service)
Federal regulations limiting commercial driver operating hours to prevent fatigue-related crashes. Key limits include 11 hours driving, 14 hours on-duty, and mandatory 30-minute breaks. HOS violations are one of the 7 BASIC categories tracked in CarrierOk's BASIC percentile data.
Power Units
The industry-standard measure of fleet size, counting only vehicles with an engine — trucks and tractors, not trailers. When someone says a carrier has 50 trucks, they mean 50 power units. CarrierOk reports power units separately from trailers via the total_power_units field, sourced from MCS-150 filings.
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