Mountain Driving: Grades, Engine Braking, and Runaway Ramps
Long downgrades are where overheated brakes fail and trucks run away. Mountain driving is about descending under control on the engine, not riding the service brakes to failure.
QUICK ANSWER
Safe mountain driving means selecting a low gear before a downgrade, using engine and auxiliary braking to control speed, and applying the service brakes only intermittently to keep them from overheating. Overusing service brakes on a long descent causes brake fade and failure. Runaway ramps exist to stop trucks that have already lost their brakes.
Descend on the Engine
The rule for a long downgrade is to select a low gear before you start down, not partway. Let engine braking and any auxiliary brake hold your speed, and use the service brakes only in short, firm applications when needed. Riding the brakes continuously heats them until they fade and stop working.
Brake Fade and Runaway Ramps
- Brake fade: overheated brakes lose stopping power.
- Gear before the grade: you cannot always downshift once rolling fast.
- Snub braking: firm, brief applications, not constant drag.
- Runaway ramp: a last resort to stop a truck with no brakes.
Pick the gear first
Once you are rolling too fast down a grade, you may not be able to get into a lower gear. Selecting the right gear before the descent is the decision that matters.
Mountain driving relies on the air brake system and skid control.
WE BUILD THIS IN VR — THE PRIME VR
We build mountain driving into VR, so drivers practice gear selection before a grade, engine and snub braking, and recognizing brake fade while the system models heat buildup and speed. Immersive downgrade practice builds the judgment that prevents runaway situations.
Book a discovery callFrequently Asked Questions
How do you control speed on a long downgrade? +
Select a low gear before starting down, let engine and auxiliary braking hold your speed, and use the service brakes in short firm applications only when needed. This keeps the brakes from overheating.
What is brake fade? +
Brake fade is the loss of braking power when brakes overheat from continuous use on a long descent. Faded brakes cannot slow the truck, which is why engine braking is used to control speed.
What is a runaway truck ramp? +
A runaway ramp is an emergency gravel or sand bed off the roadway on steep grades, designed to stop a truck that has lost its brakes. It is a last resort, not a normal stopping method.
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Train mountain driving in VR
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