If you’re pursuing a career in commercial driving, you’ve likely heard about CDL restrictions. But what exactly are they, and why do they matter?
These restrictions are specific limitations placed on a driver’s commercial driver’s license based on how their skills test was performed or what equipment was used. These restrictions can impact the types of commercial motor vehicles (CMVs) you are allowed to operate.
Knowing what each restriction means can help you avoid surprises when job hunting or upgrading your license. Our blog breaks down the most common CDL restrictions, how they’re applied, and what they mean for your career.
Why CDL Restrictions Exist
According to the Federal Motor Carrier Safety Administration (FMCSA), CDL restrictions are applied when a driver takes their CDL skills test in a vehicle that lacks certain features required for specific types of CMVs. These limitations ensure that drivers only operate vehicles they’ve been properly trained and tested on.
To avoid receiving a restriction, drivers should always take their skills test in a vehicle that matches the type they plan to drive professionally. That’s the best way to ensure you’re certified to operate the full range of vehicles in your desired class.
Common Types of CDL Restrictions
Let’s take a closer look at some of the most common CDL restrictions and what they mean:
L – No full air brake system
Unlike hydraulic brakes found in passenger vehicles, the air brakes used in large, commercial vehicles rely on compressed air to operate. The process of compressed air flowing through the system results in a slight lag time, requiring drivers to obtain a special endorsement. This restriction is issued when a driver:
- Fails the Air Brakes Knowledge Test.
- Can’t identify the air brake system components.
- Doesn’t correctly perform an air brake system check.
- Takes the test in a vehicle without a full air brake system.
With an “L” restriction, you cannot operate any CMV equipped with a full air brake system. You’ll need to retest with a proper vehicle to remove this restriction.
Z – Air over hydraulic brakes
Similar to the “L” restriction, a “Z” means the driver tested in a vehicle with an air-over-hydraulic brake system, which combines elements of both types of braking systems, instead of full air brakes. With this restriction, you’re limited to vehicles with similar braking systems and are not authorized to drive CMVs with full air brakes.
E – Automatic transmission only
If you take your skills test in a vehicle with an automatic transmission, you’ll receive an “E” restriction. This means you’re prohibited from operating vehicles with manual transmissions. Want to drive stick? You’ll need to test in a manual transmission vehicle to remove this restriction.
O – No fifth wheel connection
Drivers who test in a Class A vehicle with a pintle hook or another non-fifth wheel connection receive the “O” restriction. This limits you to operating Class A vehicles without a fifth wheel connection, commonly found in tractor-trailers.
M and N – Limited passenger vehicle class
These restrictions apply to drivers seeking passenger or school bus endorsements:
- M: If you have a Class A CDL but take your passenger or school bus test in a Class B vehicle, you’re limited to operating Class B and C buses.
- N: If you have a Class B CDL but test in a Class C vehicle for the endorsement, you’re restricted to Class C passenger vehicles.
V – Medical variance
If a driver has a medical condition that requires a variance (like a waiver or exemption), the state will place a “V” restriction on the CDL. This lets employers and authorities know that special medical documentation is on file.
CDL Restrictions and Your Career
CDL restrictions can impact your eligibility for certain jobs, especially those that require operating manual transmissions, full air brake systems, or large Class A vehicles with fifth wheel connections. If your license has any of these restrictions, it’s important to know what they mean and how they could limit your driving opportunities.
Fortunately, restrictions aren’t permanent. In most cases, you can remove a restriction by retaking the relevant skills or knowledge test using the proper vehicle. That’s why planning ahead and choosing the right training and testing conditions is critical for your career growth.
You can read more about licensing classes and required tests on the FMCSA Drivers page or search for approved schools using the Training Provider Registry.
Don’t Let Restrictions Hold You Back
Whether you’re just getting started or looking to upgrade your license, understanding CDL restrictions can help you avoid costly delays and missed job opportunities. Pay close attention to what vehicle you use during testing, and ask your instructor or examiner about any potential restrictions that could be added to your license. The more flexibility your CDL offers, the more job options you’ll have down the road.
At Pace Drivers, we know how important it is to keep your CDL in good standing—and unrestricted. That’s why we support drivers throughout the licensing process and beyond. Whether you’re navigating endorsements, preparing for a skills test, or just trying to figure out which class of license to pursue, our team is here to help.
Founded by a truck driver, Pace Drivers understands the challenges of life behind the wheel. We match qualified drivers with top companies, offer guidance on compliance and testing, and make the job search easier so you can stay focused on your goals.
Looking for your next opportunity? Let Pace Drivers help you find the right fit.
