Literally. I have been driving through northern Utah and Nevada for the last couple of days on I 80. Lots of very long up and down grades that you probably would barely notice in a car, but that are a struggle for my vehicle, or at least for me. At over 14,000 pounds and 32 feet long, it has to downshift to maintain speed on an uphill grade. My normal driving speed on a flat interstate, assuming little side wind and good pavement, is 65 MPH. I have had to slow to as little as 40 MPH along with the big trucks in a couple of places, so obviously I am driving on the far right lane, being passed by cars doing 75 MPH! I saw one double tandem FedEx truck today struggling at about 20 MPH. I passed him doing 40!
It isn't just the steepness of the grade, but the length that counts. Some are easily 2-3 miles long. You see the top of the hill, and think you have almost made it, but then when you get to the top you see another very long hill. Ditto for downhill. I don't want to lose control of this big vehicle and have the brakes fail, so I am careful to not let the speed get out of control. Many downhill grades also have curves on them where the speed limit drops, so I have to watch for those.
Another problem has been road contruction. I feel I have spent two days threading my vehicle through narrow lanes of big orange cones. Haven't hit any yet, but on some roads it is a bit scary with only gravel on the opposite side of the pavement. Makes driving challenging and very tiring, and limits the number of miles I can drive each day. Instead of managing 400 as I can in a car, I am barely able to drive 250 per day without being really tired. No stopping for naps at rest areas because they are few and far between and very hot.
Tomorrow I will be finishing up with Nevada and getting into California. Yea.