Why do trains in the US take so long?

[Filliam H. Muffman]

M A V I C, the posted speed at the curve before crossing I-5 was 30 mph, the train was traveling 79 mph before the brakes were engaged. There are a couple of locations like this where the train has to slow because the curves are too tight. Amtrak trains can climb 50% steeper grades but ice on the rails can make it very difficult to get up and down hills when there are special tracks for passenger trains with steeper grades.

There isn't a country-wide map showing speed limited locations. Curves can add 200% to the distance compared to highways going up hills.