How fast do you go

Just remember that you are not driving a lightweight short 4-wheeler, but instead have a lot of length and WEIGHT behind you. With limited braking power, a lot of weight, and a flex joint in the middle, the rig is not a high-performance sports car. Observe the 18 wheelers around, and follow their example. But remember that there are a good number if idiots driving those also, they are getting paid by the number of miles in each driving period, and some have very little experience or training. So observe the current conditions, and determine your speed accordingly. There is a lot of difference between driving the flat straight midlands, and the rolling hills and curves east of the Mississippi. Where 70 or above might be OK some places, anything over 55 will be risky in many other places.