Truck Driver Laws: Commercial Driver’s License Rules and Regulations

The requirements to obtain a CDL for operating a commercial motor vehicle and common reasons for CDL revocation and disqualification.

Whether we're talking about a semi-truck, school bus, or hazmat vehicle, to lawfully operate a commercial motor vehicle (CMV), the driver must have a commercial driver's license (CDL). To obtain a CDL, the driver must receive special training and pass certain tests and a medical examination. But drivers who hold a CDL can lose their privileges for certain criminal convictions and rule violations.

This article covers the basics of when a CDL is needed and how commercial driving privileges can be acquired and lost.

Types of Vehicles That Require a Commercial Driver's License

Generally, a CDL is required to operate any commercial motor vehicle. The "commercial vehicle designation" generally includes any vehicle weighing 26,001 or more pounds, designed to carry hazardous materials, or carrying 16 or more passengers. (Though a few exceptions to the CDL requirement exist for emergency response vehicles, RVs, and farm equipment used on or near the farm.)

Three Classes of Commercial Driver's Licenses

There are three classes of CDLs that are based on the weight of the truck and/or trailer(s) being hauled.

Combined Weight

Tractor Weight

Trailer(s) Weight

Class A

26,001 or more pounds

26,001 or more pounds

Over 10,000 pounds

Class B

26,001 or more pounds

26,001 or more pounds

10,000 pounds or less

Class C

Under 26,001 pounds

Under 26,001 pounds

10,000 pounds or less

The higher class CDLs are inclusive of lower weights. In other words, a driver who holds a class A CDL can operate any weight of CMV and/or trailer.

CDL Endorsements for Special Cargo and Types of Vehicles

The operation of certain commercial vehicles requires more than just a CDL. Endorsements are enhancements to a CDL that grant special privileges. Normally, enhancements are required for transporting passengers, carrying hazardous materials, or pulling multiple trailers. Each endorsement carries additional requirements such as extra training and testing.

Seasonal CDLs for Agricultural Work

Many states have temporary or seasonal CDLs for operating farming and agricultural commercial vehicles. The requirements for obtaining this type of CDL are more relaxed. However, these special CDLs are normally only valid for a few months and can be used only on or near the farm.

CDL Testing: What You Need to Do to Get a Commercial Driver's License

The first step in becoming a licensed commercial driver is obtaining a commercial learner's permit (CLP). An applicant for a CLP must have a valid driver's license, pass a written test covering commercial driving rules, and show proof of lawful state residency.

With a CLP, an applicant can practice driving a CMV under the supervision of a licensed commercial driver. When the applicant feels ready, he or she can take the driving test to obtain a full CDL.

Entry-Level Driver Training (ELDT). An applicant for a Class A or B CDL or passenger, hazmat, or school endorsement must also complete Entry Level Driver Training. This is a federally certified training course that provides education and behind-the-wheel training.

Medical card. Drivers with certain medical conditions—such as epilepsy—are precluded from obtaining a CDL. To verify good health, all CDL holders must possess a medical certification card from a licensed physician. Based on the health conditions diagnosed by the physician, the state can place restrictions on a CDL holder's privileges.

Age requirements. Drivers must generally be at least 18 years old to hold a CDL and at least 21 years old to operate a commercial vehicle across state lines.

CDL Revocation and Disqualification

Licensed commercial drivers are subject to special rules and regulations related to safe operation. Violating the rules or committing certain crimes can result in the loss of driving privileges.

Out-of-Service Orders

If a police officer or inspector believes the driver or vehicle to be unsafe, they can issue an out-of-service order (OSO). An OSO is a temporary order prohibiting CMV operation.

Driving during an OSO will result in license revocation. The length of the revocation depends on how many violations the driver has that occurred within the past ten years. The revocation is 180 days to one year for a first offense, two to five years for a second offense, and three to five years for a third offense.

Serious Traffic Violations

Violations such as speeding at least 15 miles per hour over the limit, following another vehicle too closely, erratic lane changes, reckless driving, and driving without a CDL in your possession are called "serious traffic violations." (Certain states also consider texting and driving and possessing alcohol in a CMV as serious traffic violations.)

A commercial driver who's convicted of two serious traffic violations within three years will be suspended for at least 60 days. Getting three or more violations in three years carries a minimum 120-day suspension.

Major Offenses

Certain violations committed by a CDL holder—called "major offenses"—will result in a mandatory one-year revocation. Major offenses include driving a CMV while under the influence, refusing a blood alcohol test, leaving the scene of a collision, driving while revoked, and negligently causing a CMV-related fatality.

Drivers who rack up two major offenses will face a lifetime CDL revocation. However, most states have programs allowing for reinstatement after ten years.

Offenses that Lead to Mandatory Lifetime CDL Ban

A commercial driver convicted of human trafficking or the transportation of controlled substances will be permanently revoked without the possibility of reinstatement.

Railroad Crossings

Commercial drivers must take certain precautions when crossing railroad tracks. Failing to properly stop or give sufficient clearance can result in a minimum 60-day, 120-day, and one-year license revocation for a first, second, and third violation in a three-year period.