The vast majority of the US interstate system involves two lanes each way with a wide median separating opposite traffic flow. There is always ample signage around exits, interchanges and whatnot. There is also a stretch that is straight and level enough to be used as a runway in wartime. I think most inclines are restricted to a max 6%-6.5% gradient (for reference, I grew up on the side of a mountain and the first climb was around 14%. You could stand on that in icy conditions and would slide down if you attempted to stand on it. Most mountains passes on the interstate also have "runaway truck" pulloutss in case a semi's brakes fail.

Most of the weirdness on the interstate system is usually caused by cities; having to adapt to preexisting conditions. As an example, I offer up Chicago. i290 is a mess. The Austion and Harlem exits are both left-handed exits. Worse yet, oncoming traffic are both given protected turns from the ramps. A lot of people dont follow the law and turn into the nearest lane. A lot of people drift, and a situation like this just breeds accidents. This is in oak park, a near west suburb. The Edens expressway (I90) also had expresslanes, which causes confusion, too. Not always open at the same time or direction.