[bigbob]

Railroads were built where it was flat as much as possible, so rail trails tend to be 2-3% grade at most and best of all, often run through small towns that the railroad left behind but which represent true America.

A Trump Country Trail, you might say!

It does take a real dedicated effort to ride across the country on shared roads with hills, traffic, and hazards. Rail trails remove most of those issues and are more scenic and can be done in much less strenuous ways.

[daniel1212]

This Man Bikes the Railroad Tracks. Can he do that? With a welder, he built two ‘rail bikes’ designed to ride the coastal line.. Nerf and Anna, his wife of 44 years, met as juniors at Davis and traveled throughout California and the Pacific Northwest by rail. - http://goodtimes.sc/santa-cruz-news/man-rail-bikes/

Then there is this: https://www.themanual.com/outdoors/best-rail-bike-tours/