1. The issue of using rockets to transport goods and people rapidly on Earth has already been discussed at length. The only real benefit is speed. The risks involved in a rocket launch are significant and will probably remain so for some time;
2. With Earth's gravity and atmosphere a chemical rocket is currently the only realistic option as nothing else has the necessary specific impulse. Railguns have been proposed but these remain impractical;
3. Certainly for traveling to other stars and even within the solar system, the energy costs and required engineering of moving sufficient people and supplies to colonize another world are so massive that the costs of building a planetary rail network on an airless network are likely to be a rounding error;
4. It's unlikely we'd want to settle more than a few places. We just don't have the same pressures that led us to colonize almost every corner of the Earth. And if we do cover such a world, it's likely that the population and industry are so large that a complex land-based transportation network will likely evolve anyway; and
5. Here's the big one: I'm increasingly convinced humanity's future won't be at the bottom of large gravity wells. It'll be in orbitals and small rocky bodies that essentially become orbitals. Entering and particularly leaving a gravity well is expensive (in energy terms). Orbitals through spin gravity can provide a much more Earthlike experience (other than, you know, the negative curvature). And most importantly: large bodies are incredibly inefficient ways to create living space in terms of area per unit volume. IIRC I saw a rough estimate that 1% of Mercury's mass could build a billion orbitals with enough living area for >10^15 people comfortably. Additionally, such orbitals would have access to virtually unlimited cheap energy through solar power.
Many of us (including Elon Musk it seems) have an irrational romantic notion of living on other worlds, particularly Mars.
The truth is, Mars isn't even remotely habitable. It does have an atmosphere but it's barely above a vacuum and certainly not high enough pressure to breathe even if it was the right gas mix (which, of course, it is not).
In some ways, Mars' atmosphere is worse than no atmosphere because all it does is allow dust to blow around and cover everything you have on the surface. Dirt and sand on Earth have been eroded over billions of years. This isn't the case on Mars. The particle are jagged, will stick to things and likely tear things apart.
Mars has no protection from radiation, is cold and has Moon-like gravity, which wouldn't be particularly comfortable.