Even high speed lines have to be built to handle at least the heaviest work trains, such as unit ballast trains, as you still have to do maintenance on those tracks -- and, in fact, high-speed lines require more maintenance than conventional lines.

I assume that conventional passenger cars would be no heavier per linear foot than a fully loaded unit ballast train.


I have long suggested that one way to recover some of the construction costs of U.S. higher-speed lines is to let fast intermodal trains run on them in the off-hours. That would work, for example, for the proposed Southeast High-speed Rail line between Washington, DC, and Raleigh, NC.

-- Ernest