Mountain driving and downgrades for the CDL
Section 2.16 of the New Jersey CDL Manual (p. 2-32) covers mountain driving: choosing a safe speed and braking on long downgrades. It is tested on the General Knowledge test.
Key facts
| Part of | the General Knowledge test (80% to pass) | NJ MVC CDL FAQ |
|---|---|---|
| Manual section | §2.16 Mountain driving | NJ CDL Manual p. 2-32 |
| Questions in CDL Mile's bank | 8 | CDL Mile, checked against NJ CDL Manual |
Key rules
- § 2.16.2p. 2-33
Newer trucks are built with low-friction parts and sleek shapes to save fuel, so less drag holds them back on the way down. They may need a lower gear to descend than to climb.
Select the Right Gear before Starting Down the Grade
- § 2.16.2p. 2-33
Forcing an automatic into a lower gear at high speed can damage the transmission and can also cost you all engine braking. Pick your low gear before the grade.
Select the Right Gear before Starting Down the Grade
Try two questions
General Knowledge · Mountain driving
Why can brakes that are out of adjustment lead to brake fade on a long downgrade?
Tap an answer to see the explanation and the manual page.
General Knowledge · Mountain driving
At the top of a grade you pass a sign reading 'Maximum Safe Speed 35.' Your truck is lightly loaded and the road is dry. What should you do?
Tap an answer to see the explanation and the manual page.
More General Knowledge topics
Sources
New Jersey Commercial Driver License Manual, version March 2025, New Jersey Motor Vehicle Commission. Page references are to its printed page numbers. CDL Mile is independent and not affiliated with the NJ MVC.
Updated for the March 2025 New Jersey CDL manual. Last checked November 5, 2026.
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