Being a good driver means being able to adjust your driving according to your surroundings. Anyone with a driver’s license can drive in a flat, smooth area. However, it takes some skills and knowledge to drive in mountainous areas with drastic changes in road grade. It’ll put you and your vehicle’s abilities to the test!
Today, we’re talking about road grade and what it means exactly. We’ll also provide several things to watch for when driving on grades. Applying these tips will help you be a better driver. Let’s dive in!
What Is Road Grade and Why Is It Important?
When you hear the term “road grade,” you might have flashbacks to the report cards or tests you received as a kid. However, the term has less to do with the road’s quality and more with its slope. Road grade refers to the amount of a road’s rise or drop in a given distance.
In a real-life scenario, a 5% grade means the road will rise or fall 5 feet for 100 linear feet. This means if you see a sign that warns of a 5% grade for the next 4 miles, you’re going up or down 1,056 feet in the next four miles of driving.
This is important information for drivers, especially those towing heavier loads. Drivers want to avoid using their brakes for extended amounts of time as it can cause them to heat up, increasing the wear and tear on them. In extreme situations, this can result in total brake failure and leave the driver unable to stop the vehicle.
What Is the Maximum Grade for a Road?
Increased road grades can be very dangerous and challenging for drivers. As a result, the maximum grade for a federally funded road in the United States is 6%. However, this increases to 7% in mountainous areas, as long as the road’s speed limit is below 60 miles per hour.
One of the most popular graded roads is I-70, which runs from Cove Fort, Utah to Baltimore, MD. The most challenging section of the road cuts through the heart of the Rocky Mountains. Drivers descend from 11,158 feet at Eisenhower Tunnel to 5,279 feet in the city of Denver. Much of the road is the maximum 7% grade the entire way.
When you get off the interstate however road grades do not have limits. While most public roads remain under 10%, we have seen road signs up to 25% in our travels.
7 Things to Watch for When Driving on Grades
No matter how long you’ve been driving, there are several things you should always watch for when driving on grades. Let’s look at what you should keep your eyes peeled for on graded roads.
Road Grade Signs
Warning signs are the yellow and black-lettered signs you see on the sides of the road. Most of these signs are diamond-shaped and depict a truck going down a hill. These alert you to expect a drastic change in the road grade.
These signs will often include the road grade percentage below the image. If you see one of these signs, you should start preparing yourself and your vehicle for the changing conditions. This may mean turning on your vehicle’s exhaust brakes or other capabilities to navigate the road.
You may be on an interstate, but the speed limits can drop considerably on graded roads. The faster your vehicle moves, the harder it will be to stop. Gravity will also cause a vehicle to gain momentum as it travels down a graded highway. You must obey the speed limits when driving on a graded road.
Speed is a leading factor in many accidents, especially on graded roads. Your speed can quickly get out of control in these areas. The super slow speed limits keep you and other drivers safe on the road. Slow down and enjoy the views.
Curve Speed Signs
Many graded roads have not only declines and inclines but also curves. You should look for signs indicating curves are ahead to adjust your speed. These signs will indicate the recommended speed for safely navigating them.
This isn’t the time to show off your vehicle’s performance or ability to handle curves. Failing to navigate one of these curves correctly can be dangerous and even deadly. Watch out for the curve speed signs and adjust your speed accordingly.
Heavy Vehicles Going Slow
It doesn’t matter whether you’re going up or down. Heavy vehicles are going to be going slow. Navigating intense road grades can be very taxing to these vehicles. They reduce their speeds to help avoid any issues with their brakes or transmissions. Laws typically require these vehicles to use the right lanes and stay out of the left lanes. However, slower traffic can be in any lane, and you’ll want to watch for them.
Smaller Vehicles Going Fast
On the opposite side of the spectrum, smaller vehicles are lighter and typically have an easier time navigating graded roads. Drivers of smaller vehicles can overestimate their ability to slow down or may change lanes quickly to avoid slower traffic. Keep an eye out for these drivers, especially in crowded situations. They can quickly cause a dangerous problem as they recklessly maneuver the highway.
Overheated Vehicles on the Side of the Road
Conquering a mountain pass or other steep grade is very taxing on a vehicle, especially towing vehicles. It’s not uncommon to see vehicles overheating on the side of the road or taking a break. Give them and their owners plenty of space as you pass by to avoid any potential accidents.
A runaway ramp can be a lifesaver if you’re experiencing a brake failure. While many think these are only available for semi trucks, that’s not true. Runaway ramps are safety features on highways in mountainous regions that drivers of any vehicle can use. However, if you need to use a runaway ramp, don’t expect your stop to feel like you’re landing on a cloud.
Runaway ramp lanes increase in depth the further you travel into them. They’re filled with sand or gravel, and the vehicle’s axles sink into them to stop the vehicle’s forward momentum. Stopping can be rather abrupt and violent, but they get the job done.
There are typically signs indicating you’re approaching a runaway ramp. As you watch the traffic around you, be mindful of vehicles trying to position themselves to utilize an upcoming runaway ramp. If you want to avoid being in an accident, move out of their way and let them pass on your right.
Tips for Driving on Roads with Grades
If you have an upcoming road trip that will have you traveling on roads with grades, we have a few tips for you. Following these tips will help ensure you and your vehicle are ready for roads with grades.
Stay Within Towing Capacities
Manufacturers set towing capacities for a reason, primarily safety. Your vehicle may be tough or strong enough to pull more weight than its rating implies. However, stopping is also important. Road grades can push your vehicle and its components to their limits. Exceeding the towing capacities of your vehicle is never a good idea.
It’s important that you know your vehicle’s towing capacities and that you weigh any loads you are towing. Not following them can put you and others on the road in a dangerous and deadly situation. We’ve seen far too many less-than-capable vehicles towing large amounts of weight during our travels.
Inspect Your Brakes
Before heading off on an adventure that will take you over graded roads, you should inspect your brakes. You don’t want to discover that you need to replace your brakes as you’re barreling down a steep grade. You can do thousands of dollars of damage and be stuck with a costly recovery bill if you have to use a runaway ramp.
If you’re not knowledgeable about vehicles, have a trusted mechanic look over your brakes and other essential components. You want to ensure you and your vehicle can safely navigate road grades during your adventures.
Pro Tip: Did driving on a grade mess up your trailer brakes? This is how to Fix RV Trailer Brakes After Failure In Mountains.
Monitor Your Engine and Transmission Temperatures
As we’ve said repeatedly, road grades can cause your vehicle to work harder than normal. This typically results in the temperatures of your engine and transmission increasing. If you’re not careful, you may cause your engine to overheat. You’ll want to keep your engine between 195 and 220 degrees and your transmission within 175 to 220 degrees.
There will likely be gauges on your dashboard that indicate the engine and transmission temperatures. Find a safe place with plenty of space to pull off the road and let your vehicle cool down. Keep your engine running so that it allows the engine fan to cool it down while you’re parked.
Some roads with intense grades will have designated spots for vehicles to park while they cool down. Don’t push the limits of your vehicle too much, or you’ll do a tremendous amount of damage and end up with an expensive repair bill.
Use Your Engine Brake on Roads With Grades
Some vehicles include engine brakes to take some of the load off a vehicle’s brakes. If yours has one, it’s a good idea to use it. This can help you control your speed without having to use your brakes. When facing an extended downward grade, these can save your brakes and avoid a dangerous situation. If you have it, use it!
Listen to Your Vehicle
The best drivers use almost all of their senses when navigating road grades, especially their sense of hearing. Turn off the music and limit conversations around you so you can listen to your vehicle. If it sounds like it’s struggling or the engine is changing tones, you might need to adjust your driving.
Being alert to how your vehicle is performing can help you avoid causing damage to it. If your vehicle is struggling, pull over to the side of the road and inspect it. Look for any abnormal wear and tear that might be causing the noise.
Pro Tip: Long driving days can make it hard to stay on alert while on the road. Use these 10 Simple Ways to Make RV Driving Days Not Suck.
Stay Alert and Safe While Driving on Roads With Grades
If you follow our tips and ensure a capable vehicle, road grades don’t have to be scary. However, extreme road grades demand respect, and you should always approach them cautiously. This helps ensure you and other drivers are as safe as possible and that everyone arrives at their destination safely.
Road grades are just one of the many hazards that can cause accidents. Learn the 5 Most Common Causes of RV Accidents (and How to Avoid Them).
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Steep grade means a grade exceeding seven percent (7%).What is a steep road grade? ›
Driving down a highway you may see a road sign that reads “6% Grade” or “Steep Grade.” The grade of the road is, essentially, its slope. The sign in Figure 1.2 indicates that the road descends at a six percent grade or a six percent slope.What is a 7% road grade? ›
A mile is 5,280 feet, so if you drive 1 mile, and climb or descend 528 feet in that mile, it's a 10% grade. If you climb or descend 370 feet, that's a 7% grade, or if you climb or descend 264 feet that's a 5% grade. Carried to it's extreme, a 30% grade means you go up or down almost 1600 feet in a mile.How steep is a 6 grade on a road? ›
Answer and Explanation: A 6% grade is the measure of the steepness of a section of road. The steepness of the road is the slope of that road, or the change in elevation over a given distance. A 6% grade is a slope of 6100 , which expresses that over a 100 unit distance, the road will rise 6 units.What is the steepest road grade allowed? ›
While federal law requires interstate highways to have a maximum grade of six percent, state highways are a different story. Pennsylvania maintains a highway with a 14.5-degree slope, and California is even steeper, with a highway at a whopping 26-degree grade.How steep is 1 in 7? ›
It is a fraction of x units of vertical to y units of horizontal. The British system makes x = 1, ie 1 in 7, which would be a fairly steep road. The European system expresses the gradient as a percentage, ie it makes y = 100. Here 1 in 7 would be about 14%.Is 20% grade steep? ›
Around 11-20% is considered moderate and gradients above 20% are considered “steep”.How steep is a 14% grade? ›
|1°||1 : 57.29||1.75%|
|5°||1 : 11.43||8.75%|
|10°||1 : 5.67||17.63%|
|15°||1 : 3.73||26.79%|
If the gradient is given as 7% , which means the same as 7100 , it would mean a rise of only 7 units along a run of 100 .
Suppose you climb eight feet as you go forward 100 feet. That's an 8% gradient. Or suppose you go up 100 feet as you go forward 100 feet. That's a 100% gradient, and is also going to be pretty hard to get your tires to not slip a little bit.How steep is a 30% grade? ›
30 Degrees: This has enough drop to cause you to slip and slide if you fall. It's average for a steep section in a blue (intermediate) run. Will cause adrenaline increases in most average skiers.What is the steepest grade on US roads? ›
Waipio Valley Road on the island of Hawai'i is said to be the steepest rural road in the United States, with some grades approaching 45%.How steep is a 60 percent grade? ›
|60°||173%||1 in 0.58|
|47.7°||110%||1 in 0.91|
|45°||100%||1 in 1|
|30.1°||58%||1 in 1.724|
Percent of slope is determined by dividing the amount of elevation change by the amount of horizontal distance covered (sometimes referred to as "the rise divided by the run"), and then multiplying the result by 100.How steep is a 3 grade? ›
Therefore, 3% means 3/100. Slope = rise/run and thus, a 3% slope has a rise of 3 and a run of 100. As an example, in 100 feet the road or ground will rise 3 feet. Slope may also be thought of and the tangent of an angle.What is the maximum incline for a road? ›
For Category A Roads, gradients should not be steeper than 12.5%. should not be above 8%. Due to loss of tractive eﬀorts of the vehicle on curves it is recommended to ease the gradients ….Is an 8% hill steep? ›
8% may not look much on paper, but it is a steep hill in normal parlance.How steep is a 45% slope? ›
BCA Slope Meter
A 45-degree pitch is equivalent to a 100-percent grade, and both mean that a run descends one vertical foot for each horizontal foot. “In perspective, a very steep highway-pass road is approximately 7 percent or about 4 degrees,” according to the Highlands Extreme Guide trail map.
Many municipalities distinguish between "moderately steep slopes" of 15-25% and slopes defined as "very steep", "prohibitive", or "severely steep" as slopes greater than 25%. Stricter limits for defining steep slopes may apply to areas with specific geographic or geological constraints.
o Degree of slope is measured in degrees from horizontal (0 – 90) ▪ A 45-degree slope is a 100 percent grade.How steep is a 9% slope? ›
|Slope (%)||Approximate degrees||Terminology|
|9 - 15||5 - 8.5||Moderate slope|
|15 - 30||8.5 - 16.5||Strong slope|
|30 - 45||16.5 - 24||Very strong slope|
|45 - 70||24 - 35||Extreme slope|
Steep Slope: 10/12 and above
Any pitch that's at least 10/12 (39.81 degrees) is considered steep slope. This includes 10 over 12, 11 over 12, 12 over 12, and pitch where the rise is greater than the run.
Baldwin Street in Dunedin, New Zealand, may be the steepest residential street in the world; it reportedly averages 1:3.41 (16.33° or 29.3%) for 161 meters but its maximum is claimed to be 35% for an unknown distance. Canton Avenue in Pittsburgh is said to have a 37% grade; the length of that grade is unknown.What is the steepest grade in the world? ›
Fford Pen Llech, Harlech, Wales – 37.45%Does 7 degrees make a difference? ›
The Department of Energy estimates savings of about 1 percent for each degree of thermostat adjustment per 8 hours, and recommends turning thermostats back 7 to 10 degrees from their normal settings for 8 hours per day to achieve annual savings of up to 10%.What is the degree 7? ›
Answer: The degree of a constant polynomial (such as 7) is zero, as the polynomial can be thought of as 7x0. The degree of the zero polynomial (0) is usually considered to be undefined.Which state has the steepest road? ›
Canton Avenue is a street in Pittsburgh's Beechview neighborhood which is the steepest officially recorded public street in the United States.What road in the United States has the steepest grade? ›
Canton Avenue in Pittsburgh's Beechview neighborhood is a monster hill with a 37% grade -- a struggle for walkers and drivers alike. Just how steep is this street? Tap the video player above to see it! Related: Welsh street named steepest in world, edging out Pittsburgh's Canton Ave.
It doesn't matter exactly what it means, 20% is steeper than 10%. In surveying 20% is interpreted as 20% of a right angle (i.e. a brick wall) and so would be 18 degrees.