Driving an 18-wheeler across steep mountains grades and winding passes can be scary to even a seasoned truck driver. It is especially difficult during the winter months when snowfall and strong crosswinds in the higher elevations can be hazardous and unpredictable. Operating a big rig through snow and ice is always dangerous and should not be attempted unless absolutely necessary. If the weather conditions require you to install tire chains on a big truck, you may be better off to sit out the storm, but this is not always the case.
Climbing a mountain in a big rig requires the driver to downshift to maintain pull on the trailer. If a driver misses a gear the truck can come to a complete stop and endanger him and other drivers. The driver needs to keep the rotation per minute (rpm) high without over tacking the engine. If the tachometer drops below 1,200 rpms, downshift to the next lower gear; being careful not to allow the rpms to exceed 2,200. You will want to shift as smoothly as possible on icy roads.
Descend the mountain or downgrade in the gear lower than the gear used to crest the summit. Most modern trucks are also equipped with an engine retarder or Jake Brake; use it to help you maintain a safe speed on the downgrade. Additional braking may still be required when the Jake Brake is being used. The use of the Jake Brake is not recommended on slippery roads.
Apply light, steady pressure to the brake pedal so you do not overheat the brakes. Overheated brakes can result in melted air lines and a complete loss of air brakes. Avoid a hard application of the brakes. A stable breaking procedure will work better and reduce the likelihood of overheating the brakes. Driving down a mountain in a big truck can be extremely dangerous and should only be attempted by an experienced driver or with a certified instructor in the truck supervising.
Keep the nose of the truck closer to the high side of curves when driving along tight winding roads. This is done to maintain the lane and allow for the off-tracking of the trailer as it is pulled along. Slower speeds and tighter curves result is more off tracking by the trailer. The driver has to be especially careful not to allow the trailer tandems to drop off the edge of the road or colliding with the side of the mountain.
Practice downshifting and driving on a downgrade when you’re hauling a light load to get yourself familiar with the procedure. It will be less dangerous in the event you make a mistake and will help the required actions to become more like second nature.
Winter mountain driving is the most dangerous operation of a big rig and you should be extremely careful. Tire chains may be required and you should be trained in their proper installation prior to having to use them.