What is the maximum grade allowed on US interstate highways?
6%
Maximum grade: The maximum permissible vertical angle, or grade, along the highway is determined from terrain and design speed, with up to 6% generally allowed in mountainous areas, 5% in rolling terrain, and 4% on level terrain. An additional 1% is allowed in urban areas.
What is the highest pass on I-80?
The summit between Laramie and Cheyenne (elevation 8,640′) is the highest point on the transcontinental I-80 Route.
Where do you cross the Continental Divide on I-80?
Interstate 80 crosses the Continental Divide, first at Milepost 158 (elevation 6,930 feet above sea level) and again at Milepost 206 (elevation 7,000 feet above sea level), at the Hadsell Road Exit.
What is the steepest grade on i80?
Most major U.S. highways don’t exceed a 6 percent grade, the magic number for the preferred maximum steepness of a road. Parleys Canyon (I-80) has a maximum grade of 6 percent.
What is the steepest grade on an interstate?
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.
Is Highway 80 mountainous?
From the city of San Francisco to four miles west of the Hudson River at Teaneck, New Jersey, I-80 traverses various terrain and 11 states. Its highest point is located at Sherman Hill Summit in Wyoming between Laramie and Cheyenne at an elevation of 8640 feet.
What is the grade of Donner Pass?
7.5 percent
The grade on the eastern side of Donner Pass is 7.5 percent. It climbs 1,152 feet (351 meters) from Donner Lake in 2.9 miles (4.7 kilometers) . The road is narrow with extremely sharp curves. We strongly recommend that you don’t attempt it while towing a large trailer.
What is the steepest grade on I 75?
As the clouds thicken, the windshield beads with fine, silver-dark drops. “Jellico is the steepest grade on I-75. You might get down to 20 miles an hour,” said Newell Lacky, 49, who had stopped to nurse some java at the Amoco North-South Auto-Truck Good Food You Betcha at Clinton.
Is I-80 through Wyoming flat?
Wyoming: In the state of Wyoming, I-80 reaches its maximum elevation of 8,640 feet (2,633 m) above sea level between Cheyenne and Laramie, Wyoming. Farther west in Wyoming, the interstate passes through the Red Desert and over the Continental Divide.
What is a 6% grade?
A road sign indicating a 6% grade, or 6% slope. A six percent slope means that the road elevation changes 6 feet for every 100 feet of horizontal distance (Figure 1.3). Figure 1.3. A road climbs at a gradient of 6 percent.
Is 80 open over Donner Pass?
Interstate 80 over Donner Summit is open year-round, but conditions on the pass in the winter often cause temporary closures.
