I think this is true in a world without self driving cars but I'm not so sure about a world with them. The key thing that roads give you over railways is flexibility. Roads require comparatively less planning and allow goods to be shipped point to point without having to change vehicles. Until now they've come with the huge costs of requiring a person to sit at the wheel and a lot of liability because that person might crash the truck and kill someone. If both of those costs go away I think roads might be better infrastructure than railroads.
On the one hand, rail is much cheaper per-mile than traditional roads, for both construction and maintenance.
Rail is also more efficient in terms of goods hauled per unit of fuel spent, and controlling carbon emissions from rail is massively easier than doing so from individual trucks.
However, rail itself is fundamentally... unegalitarian, maybe? Rail lines can only be used by those with the capital to run rolling stock between well-specified endpoints (typically large urban centers), and on specified timetables.
The system as it exists in the US right now is less efficient, but opens up a lot of possibilities. For example, I live in Japan and don't own a car right now, which means that I basically can't go backpacking. But if I rent a car, then I can go out to more remote places that are less frequented by the non-hiking masses, and actually enjoy some of the sheer beauty of the Japanese countryside.
Self-driving cars and trucks really do seem to bridge the gap between "cheap rail transport" and "private vehicles for everything", but I worry that they will continue just to be a convenience for the well-off (which is what Uber and Lyft currently are, frankly), rather than a means by which to make transportation available to everybody.
