According to the Trump that’s exactly what he wants, countries to sell off the bonds they have in exchange for super long term bonds that defer interest for like 100 years.

In terms of getting to an exact location, the most efficient is no vehicle, walking.

Cars are less efficient, followed by busses, then probably trains, then boats, then airplanes (unless you parachute).

Cars are the least efficient in terms of moving large numbers of people from places they can then walk from.