What Is the CDL General Knowledge Test?
The CDL General Knowledge test is the core written exam required for all Commercial Driver's License applicants. It covers fundamental knowledge every commercial driver needs to operate safely on public roads. The test consists of 50 multiple-choice questions.
| Feature | Details |
|---|---|
| Questions | 50 |
| Passing Score | 40/50 (80%) |
| Time Limit | 60-90 minutes |
| Format | Multiple choice |
Topic Breakdown
| Topic | Questions | Key Focus |
|---|---|---|
| Vehicle Inspection | 10-12 | Pre-trip procedures, what to check |
| Space Management | 10-12 | Following distance, scanning, cushion of safety |
| Hazard Perception | 8-10 | SEE method, night driving, emergencies |
| Emergency Procedures | 8-10 | Brake failure, blowout, hydroplaning |
| Regulations | 8-10 | BAC limits, cargo securement, weight limits |
Passing Score and Retakes
You need 40 out of 50 (80%). Most states allow same-day or next-day retakes. Some require a 30-day wait after three failures. Check with your state DMV for specific retake policies.
Effective Study Strategy
- Read the manual — Download your state's free CDL manual
- Take practice tests — Identify weak areas
- Memorize key numbers — Following distance (6 sec), PSI values (60-100-125-150), BAC (0.02%-0.04%)
- Study in sections — One topic at a time
Test Day Tips
- Arrive early — some DMVs require 15-30 minute early check-in
- Bring required documents: ID, residency proof, CLP application
- Read each question carefully — wrong answers test attention to detail
- Eliminate obviously wrong answers first
- Mark uncertain questions and return to them
Practice with our free CDL practice quiz. Source: FMCSA Regulations 49 CFR Part 383