Unless you’re a regional truck driver operating among the plains states, chances are you are going to have to drive on, over or around a mountain at some point or another. It’s incumbent on professional truck drivers to know how to operate their commercial motor vehicle when traversing mountain passes.
The first thing to remember is that in mountain driving, gravity plays the leading role. Whether you are on an up or downgrade, gravity runs the show. Because of this, it is vitally important that your vehicle’s brakes are in excellent working condition.
If your vehicle is using an air brake system, consider checking for the following:
- Ensure compressor is at full reservoir pressure;
- Check for pressure drops on full application within stated limitations;
- Slack adjusters for full push rod travel;
- Listen for audible air leaks;
- Ensure proper trailer protection valve operation.
Handling upgrades is more complicated than just stepping on it. The force of gravity causes your vehicle to slow down on an upgrade, which makes it difficult to maintain a constant speed.
The steepness, length of the grade and weight of the load all play a major role in what gear you select to travel the upgrade. The steeper and longer the grade and/or the heavier the load, you’ll want to make sure you are in a lower gear. If you select a gear too high for the conditions you are putting on the engine, you could overheat or stall out.
Make sure you closely monitor the vehicle’s gauges as you head uphill. When you are driving uphill, your vehicle’s components are working much harder than when you are traveling on a flat roadway.
This extra work causes your engine to generate more heat. If your vehicle gauge indicates higher-than-normal temperature readings or a decrease in oil pressure, pull over at a safe area and let the vehicle cool down.
When you are traveling uphill on a multi-laned road, always travel in the right lane. This allows smaller, faster passenger cars to safely pass you. Always pay close attention to the traffic surrounding your vehicle, especially that to the front and the rear.
When you are on a downgrade, gravity’s forces are pulling your vehicle faster. To help combat those forces, make sure you are always traveling at an appropriate speed, in the right gear, and applying proper braking technique.
An appropriate speed should be considered one that is slow enough to allow the brakes to hold the vehicle without resulting in overheating or fading. If you have to continually apply pressure, the brakes will eventually fade until you have little to no stopping control.
Always consider the total weight of vehicle, cargo, road and weather conditions when choosing the right speed. As with upgrades, always stay to the right on a downgrade. Also be aware of any road signs that indicate a maximum vehicle safe size.
Rather than relying on the brakes, the braking of the engine should be the primary way to control the vehicle’s speed. Shift the engine into a lower gear and use engine braking to lower RPMs.
Proper Braking Technique
When it comes to navigating up or downgrades, you’ve got to know the right technique. Try following this method when driving with proper braking technique:
- Identify a safe speed for the load and grade.
- When you have reached the speed, apply the brakes just hard enough to feel a definite slowdown.
- Once you have reduced the vehicle’s speed by 5 mph, release the brakes.
- When the vehicle’s speed increased back to or above the safe speed you previously identified, repeat the first three steps.
For steep mountain downgrades, escape ramps are built into the sides of the road. They are designed to help safely stop a runaway vehicle.
There are four basic types of escape ramps:
- Gravity ramps: Constructed of pea gravel with mounds of sand or gravel at the end of the ramp.
- Sand piles: Mounds or ridges of sand tall enough to drag on the undercarriage of the vehicle.
- Arrester beds: Beds of loose material that cause the vehicle to sink.
We hope you’ve enjoyed this look at navigating mountain passes. The best way to stay safe during treacherous navigation is to respect the mountain. Practice these tips for safe driving, day-in and day-out.