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Mountain Grade Information
No information here, nor in the book is intended to tell you how to navigate a mountain grade – it is only to give you an idea of the location of the grade as well as how steep and/or how long some of the better-known grades are.
Sample of Mountain Info in Driver's ABC's
A Few of the Well Known Grades in the U.S.
Q: What does the (%) percentage mean?
A grade has a percentage and a length. For example, let’s take a 6% grade that is 10 miles long. This means that for every 100 foot of roadway, you are going to drop 6 feet. For each 1% of grade you’d descend 52.8 feet, since 5,280 feet equals one mile.
Note that the number of feet descended on a 4% grade that is 6 miles in length is nearly the same as a 6% grade that is 4 miles in length. The drop is nearly the same BUT on the 4% grade, the descent is spread out over more territory - making it a less hazardous descent.
Always, always respect them - never think you "know" a mountain! Every time you go over it, the situation is different. Your load changes, the brakes are in a different condition, you probably have a different trailer, anyway, the weather changes, etc, etc!
When climbing a mountain grade, unless you're lightly loaded or empty, chances are you'll lose a significant amount of speed. Move over to stay out of the way of other traffic. Put your four way flashers on when moving much slower than other traffic.
Go down the mountain in a low enough gear!!! It is far easier to upshift on a downgrade than to downshift on a downgrade!!!!!!
Never, ever, never go down a grade in Neutral. Avoid shifting – you could "lose" it and be stuck in Neutral.
Do not use the jake brake (engine retarder) when road is wet and especially and never when it’s slick. Do not become "spoiled" on a jake brake -- they are mechanical and can and do fail. If you've learned to drive in the summer and have only went down grades with the assistance of a jake brake, in the winter you will be at a disadvantage. The first time you descend a new mountain grade, try it without the jake so you'll know how to do it if it ever goes out or if it is slick and therefore, useless.
When climbing a grade when it's hot, watch your temperature gauge closely. If you have a manual engine fan, you may need to run it. It decreases power, but it’s better than overheating.
When descending a mountain grade, you could try turning the engine fan on also. It takes power from the engine. It won’t help much but every little bit counts!
The following is an example taken from "Driver's ABC's" -- Mountain Information section. In the book, there are 18 more states detailed.
I-70 "Eisenhower", approx. MM 215 to MM 205,
starts after coming out of the tunnel, Westbound
I-70 "Eisenhower", approx. MM215 to Georgetown,
CO, starts after coming out of the tunnel, Eastbound
I-70 Starting approx. MM 253, Eastbound
I-70 Starting approx. MM 246, Westbound
I-70 "Vail Pass", approx. MM 189 to MM 179,
Westbound The information you’ll find in "Driver's ABC's" -- Mountain section:
*You'll see the word "approx." constantly. That is because it is very difficult to pinpoint exactly where each and every grade begins. Do NOT take these milemarkers for exact! The last thing this author wants is for a person to use these numbers as exact and find themselves in too high of a gear on the way down a grade!
*Please note that sometimes you'll see "MM", which stands for "Mile Marker" and sometimes you'll see "Exit #". This is because some states do not have mile markers and exit numbers that match so the clearest description was used. (For information about Mile Markers VS Exit Numbers, see Interstate System)
What are those drivers talking about?
Any names in "quotes" are nicknames that drivers use.
The mile marker numbers, grade depth and length are all approximates - believed to be as close to accurate as possible. These are by no means all the grades in the United States! The grades listed are the ones most commonly encountered by heavy-truck drivers since most of them are on U.S. Interstates or on the designated network. Those listed that are on US Routes or State Highways are included because they are on a common truck route. The information is arranged in alphabetical order, by state name.
Just a few of the better known grades in the United States:
Notice the gauge readings... RPM's read about 1600. Speed reads approximately 26 mph. The speed limit on this grade is 35 mph. The driver has the RPM's and speed "set" so that when at maximum recommended RPM's (about 1800-1900), the speed should be just about 35 mph.
With the Jake Brake on, this setting will maximize the Jake's effect. Keep in mind, though, that Jake Brakes are mechanical and CAN FAIL. They should never be used on slippery surfaces, either.
This article is an excerpt from "Driver's ABC's, Surviving the First Year," modified for the Web. This article may appear in more detail or in a different format in the book version. Copyright 2000-2007, Creative Curriculum FTTI, All Rights Reserved, no reprint without permission.
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