Could some of the benefits of the Hyperloop be transitioned to HSR? What if one could build the HSR on pylons and the tube idea but use electric high-speed trains. Lower cost per mile to build since it is modular and not built on site. One might even be able to lighten the trains a bit. the low-pressure tubes might still be applied to reduce air friction. It might not be quite as fast or low power to operate but still have advantages over HSR.