Endorsements add privileges to your CDL, but CDL restrictions take them away. If you tested in an automatic truck, you’ll be restricted from driving manuals. If you didn’t test in a vehicle with air brakes, you can’t drive one on the road. Restrictions define what you’re not authorized to operate, and misunderstanding them can turn a routine job assignment into a major violation.
A CDL restriction is a limitation printed on your commercial driver’s license that restricts the type of vehicles or equipment you may operate. Restrictions are coded with letters and are added to your CDL based on how you completed your skills test, your medical condition, or the type of vehicle you used during testing. Common restrictions include L (no air brakes), E (no manual transmission/automatic only), K (intrastate only), O (no semi-trailer), M (no Class A passenger vehicle), N (no Class C passenger vehicle), P (no passengers in CMV), S (no school bus), T (no doubles/triples), and V (medical variance required).
Why It Matters for Your Driving Test
CDL restrictions are tested on the written exam because they directly affect your employment options and legal driving privileges. You need to know which restrictions exist, what causes them, and how to remove them. If you take your skills test in an automatic, you’ll receive an E restriction—which eliminates you from many driving jobs that require manual transmission skills. Choosing your test vehicle wisely is one of the most important decisions in your CDL journey.
What You’ll See on the Road
Restrictions are printed directly on your CDL card under “Restrictions.” Carriers check your restrictions before assigning routes. At weigh stations, inspectors verify that your CDL matches the vehicle and equipment you’re operating. Operating a vehicle that exceeds your restriction is the same as driving without the proper class of license.
“You test for your Class A in an automatic truck because that’s what your school had available. You pass and get your CDL—with an E restriction. Now a carrier offers you a great job, but their fleet is all 13-speed manuals. You can’t take the job until you remove the restriction by retesting in a manual.”
Common Pitfall & Pro Tip
⚠️ Pitfall: Testing in an automatic to make the skills test easier, then being surprised by the E restriction that limits your job opportunities. Similarly, testing in a vehicle without a full air brake system results in the L restriction—one of the most career-limiting restrictions in trucking, since nearly all Class A trucks use air brakes.
💡 Pro Tip: If possible, test in a manual transmission truck with a full air brake system to avoid both the E and L restrictions. These two restrictions are the most common and the most limiting for new drivers. It’s worth the extra practice to test without them, even if it’s harder.
Memory Aid for CDL Restrictions
Think “L and E are the Big Two”—L means no air brakes (huge), E means automatic only (limits jobs). Most other restrictions are less common but still important. Avoid L and E by testing in a manual, air-brake-equipped vehicle, and you’ll keep your career options wide open.
Driving Test Connection
Written exam questions ask you to identify what specific restrictions mean, what causes them, and how they affect driving privileges. You may be given a scenario where a driver has certain restrictions and asked whether they can legally operate a specific vehicle.
Related Driving Concepts
Restrictions are the flip side of CDL endorsements—endorsements add privileges, restrictions limit them. The most impactful restriction is the air brakes restriction (L), which prevents you from operating air-brake-equipped vehicles. The intrastate restriction (K) limits you to driving only within your home state. Restrictions can often be removed by retesting with the appropriate vehicle.
Quick Reference
✓ Key Rule: You cannot operate a vehicle that requires equipment or skills beyond your CDL restrictions.
✓ Exam Priority: Routine – Written exam questions on restriction codes and effects.
✓ Driver Actions:
- Know the restriction codes before you test—choose your test vehicle wisely.
- Test in a manual transmission to avoid the E restriction.
- Test in a full air brake vehicle to avoid the L restriction.
- Check your CDL card for restrictions after receiving it.
- Retest with appropriate equipment to remove unwanted restrictions.
- Inform carriers of your restrictions during the hiring process.
Restrictions shape your career options from day one. Test smart, avoid the big two (L and E), and keep every door open for the opportunities ahead.